Tüm alıştırma soruları

2131 soru

Soru 1581Soru

For all real numbers x0x \neq 0 and x1x \neq 1, the function ff is defined by f(x)=x1xf(x) = \frac{x - 1}{x}. The composite function notation fn(x)f^n(x) is defined by f1(x)=f(x)f^1(x) = f(x) and fn(x)=f(fn1(x))f^n(x) = f\left(f^{n-1}(x)\right) for all integers n2n \ge 2. What is the value of f2026(5)f^{2026}(5)?

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Cevap: 45\frac{4}{5}

Cevap

45\frac{4}{5}
Evaluating successive compositions of f(x)=x1xf(x) = \frac{x-1}{x} starting at x=5x = 5 yields f1(5)=45f^1(5) = \frac{4}{5}, f2(5)=14f^2(5) = -\frac{1}{4}, and f3(5)=5f^3(5) = 5. This produces a repeating sequence of period 3. Since 20261(mod3)2026 \equiv 1 \pmod 3, f2026(5)f^{2026}(5) equals f1(5)=45f^1(5) = \frac{4}{5}.

Adım Adım Çözüm

1
Evaluate the first iteration f1(5)f^1(5).
f1(5)=f(5)=515=45f^1(5) = f(5) = \frac{5 - 1}{5} = \frac{4}{5}.
Substitute x=5x = 5 into the definition of f(x)f(x).
2
Evaluate the second iteration f2(5)=f(f1(5))f^2(5) = f(f^1(5)).
f2(5)=f(45)=45145=1545=14f^2(5) = f\left(\frac{4}{5}\right) = \frac{\frac{4}{5} - 1}{\frac{4}{5}} = \frac{-\frac{1}{5}}{\frac{4}{5}} = -\frac{1}{4}.
Substitute x=45x = \frac{4}{5} into the function definition.
3
Evaluate the third iteration f3(5)=f(f2(5))f^3(5) = f(f^2(5)).
f3(5)=f(14)=14114=5414=5f^3(5) = f\left(-\frac{1}{4}\right) = \frac{-\frac{1}{4} - 1}{-\frac{1}{4}} = \frac{-\frac{5}{4}}{-\frac{1}{4}} = 5.
Substitute x=14x = -\frac{1}{4} into the function definition.
4
Identify the periodic pattern and evaluate f2026(5)f^{2026}(5).
Since f3(5)=5f^3(5) = 5, the function values repeat in a cycle of length 3: (45,14,5)(\frac{4}{5}, -\frac{1}{4}, 5). Dividing 2026 by 3 yields 2026=3×675+12026 = 3 \times 675 + 1, giving a remainder of 1. Therefore, f2026(5)=f1(5)=45f^{2026}(5) = f^1(5) = \frac{4}{5}.
The remainder determines the equivalent position in the 3-element repeating sequence.

Anahtar Kavram

Nested Function Composition and Periodicity
Soru 1582Soru

If xx is a real number that satisfies 32x9|3 - 2x| \le 9, what is the maximum possible value of x5|x - 5|?

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Cevap: 8

Cevap

The maximum possible value of x5|x - 5| is 8.
Solving 32x9|3 - 2x| \le 9 yields 932x9-9 \le 3 - 2x \le 9. Subtracting 3 gives 122x6-12 \le -2x \le 6. Dividing by 2-2 and reversing inequality signs results in 3x6-3 \le x \le 6. To maximize x5|x - 5|, find the point in [3,6][-3, 6] that is farthest from 5. Evaluating at the endpoints gives 35=8|-3 - 5| = 8 and 65=1|6 - 5| = 1. The maximum possible value is 8.

Adım Adım Çözüm

1
Solve the absolute value inequality 32x9|3 - 2x| \le 9.
932x9-9 \le 3 - 2x \le 9
By definition of absolute value, uk|u| \le k means kuk-k \le u \le k for k0k \ge 0.
2
Isolate 2x-2x by subtracting 3 from each part.
122x6-12 \le -2x \le 6
Subtracting a constant from all parts preserves the inequality direction.
3
Isolate xx by dividing each part by 2-2.
3x6-3 \le x \le 6
Dividing an inequality by a negative number flips the inequality signs.
4
Determine the maximum value of x5|x - 5| over the interval [3,6][-3, 6].
Maximum occurs at x=3x = -3, where 35=8|-3 - 5| = 8.
The expression x5|x - 5| represents the distance from xx to 5 on the number line. The endpoint x=3x = -3 is furthest from 5.

Anahtar Kavram

Linear inequalities and absolute value as distance on a number line
Soru 1583Soru

The table below shows the frequency distribution of daily rainfall, in millimeters, recorded across 50 weather monitoring stations during a storm event.

Daily Rainfall (mm)Number of Stations
0 to under 1010
10 to under 2015
20 to under 3017
30 to under 405
40 to under 503

What percentage of the stations that recorded at least 10 mm of daily rainfall recorded less than 30 mm of daily rainfall?

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Cevap: 80%80\%

Cevap

80%80\%
To find the desired percentage, first identify the total number of stations that recorded at least 10 mm of rainfall. This includes the intervals 10 to under 20, 20 to under 30, 30 to under 40, and 40 to under 50, giving 15+17+5+3=4015 + 17 + 5 + 3 = 40 stations. Next, find how many of these 40 stations recorded less than 30 mm. These fall into the 10 to under 20 and 20 to under 30 intervals, which total 15+17=3215 + 17 = 32 stations. Calculating the relative percentage gives (32/40)×100%=80%(32 / 40) \times 100\% = 80\%.

Adım Adım Çözüm

1
Determine the conditional base (denominator)
Sum the frequencies for all intervals representing at least 10 mm: 15+17+5+3=4015 + 17 + 5 + 3 = 40 stations.
The question specifies 'stations that recorded at least 10 mm of daily rainfall', restricting our population base to this subset.
2
Determine the target subgroup frequency (numerator)
Sum the frequencies for intervals within the base that are also less than 30 mm (the 10 to under 20 and 20 to under 30 intervals): 15+17=3215 + 17 = 32 stations.
We need to count the stations that meet both conditions: at least 10 mm and less than 30 mm.
3
Calculate the percentage
3240×100%=0.80×100%=80%\frac{32}{40} \times 100\% = 0.80 \times 100\% = 80\%.
Divide the target subgroup count by the conditional base count and multiply by 100.

Anahtar Kavram

Grouped frequency table interpretation with conditional percentages
Tahmini Süre:1m 30s
Soru 1584Soru

If xx is an integer that satisfies both 2x+17|2x + 1| \le 7 and 5x2<1\frac{5 - x}{-2} < -1, how many possible values of xx are there?

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Cevap: 7

Cevap

There are 7 possible integer values of xx.
Solving 2x+17|2x + 1| \le 7 yields 4x3-4 \le x \le 3. Solving 5x2<1\frac{5 - x}{-2} < -1 requires flipping the inequality symbol when multiplying by 2-2, resulting in 5x>25 - x > 2, which simplifies to x<3x < 3. Taking the intersection of 4x3-4 \le x \le 3 and x<3x < 3 gives the interval 4x<3-4 \le x < 3. The integers in this range are 4,3,2,1,0,1,2-4, -3, -2, -1, 0, 1, 2, totaling 7 integers.

Adım Adım Çözüm

1
Solve the absolute value inequality 2x+17|2x + 1| \le 7.
72x+17    82x6    4x3-7 \le 2x + 1 \le 7 \implies -8 \le 2x \le 6 \implies -4 \le x \le 3.
An absolute value inequality of the form uk|u| \le k (for k0k \ge 0) expands to kuk-k \le u \le k.
2
Solve the rational inequality 5x2<1\frac{5 - x}{-2} < -1.
5x>(1)(2)    5x>2    x>3    x<35 - x > (-1)(-2) \implies 5 - x > 2 \implies -x > -3 \implies x < 3.
Multiplying or dividing an inequality by a negative number requires reversing the direction of the inequality sign.
3
Find the intersection of the two solution sets and count integer solutions.
4x<3-4 \le x < 3. The integer values satisfying this inequality are 4,3,2,1,0,1,2-4, -3, -2, -1, 0, 1, 2, which gives a total of 7 integer values.
The solution must satisfy both conditions simultaneously.

Anahtar Kavram

Solving combined linear and absolute value inequalities while correctly reversing inequality signs when multiplying or dividing by negative values.
Tahmini Süre:1m 30s
Soru 1585Soru

Two water pumps, Pump A and Pump B, working simultaneously at their respective constant rates, can fill an empty storage tank in 44 hours. If Pump A operates alone at its constant rate for 22 hours and then Pump B operates alone at its constant rate for 77 hours, the tank is also filled completely. How many hours would it take Pump A, working alone at its constant rate, to fill the entire storage tank?

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Cevap: 203\frac{20}{3} hours

Cevap

203\frac{20}{3} hours (or 6236\frac{2}{3} hours)
The correct answer is derived by setting up two linear equations representing the total work accomplished: 4rA+4rB=14r_A + 4r_B = 1 and 2rA+7rB=12r_A + 7r_B = 1. Solving this system gives Pump A's rate rA=320r_A = \frac{3}{20} tanks per hour. The time required for Pump A working alone is the reciprocal of its rate, which equals 203\frac{20}{3} hours.

Adım Adım Çözüm

1
Define variables and formulate the system of linear equations
Let rAr_A be the rate of Pump A (tanks/hour) and rBr_B be the rate of Pump B (tanks/hour).
Combined work equation: 4(rA+rB)=1    4rA+4rB=14(r_A + r_B) = 1 \implies 4r_A + 4r_B = 1
Sequential work equation: 2rA+7rB=12r_A + 7r_B = 1
Work done equals rate multiplied by time, and completing one full tank corresponds to total work =1= 1.
2
Express rBr_B in terms of rAr_A using the first equation
rA+rB=14    rB=14rAr_A + r_B = \frac{1}{4} \implies r_B = \frac{1}{4} - r_A
Simplifying the combined rate equation allows substitution into the second linear equation.
3
Substitute rBr_B into the second equation and solve for rAr_A
2rA+7(14rA)=1    2rA+747rA=1    5rA=174=34    rA=3202r_A + 7\left(\frac{1}{4} - r_A\right) = 1 \implies 2r_A + \frac{7}{4} - 7r_A = 1 \implies -5r_A = 1 - \frac{7}{4} = -\frac{3}{4} \implies r_A = \frac{3}{20}
Eliminating rBr_B isolates rAr_A as a single-variable linear equation.
4
Calculate the time required for Pump A to fill the tank alone
TimeA=1rA=1320=203 hours\text{Time}_A = \frac{1}{r_A} = \frac{1}{\frac{3}{20}} = \frac{20}{3}\text{ hours}
The total time to complete 1 unit of work is the reciprocal of the unit work rate.

Anahtar Kavram

Formulating and solving systems of two linear equations in two variables derived from work-rate relationships.
Soru 1586Soru

In the xyxy-plane, line 1\ell_1 is defined by the equation 3x4y=123x - 4y = 12. Line 2\ell_2 is perpendicular to line 1\ell_1 and intersects the positive yy-axis at the point (0,d)(0, d). If the area of the triangular region bounded by line 1\ell_1, line 2\ell_2, and the yy-axis is 2424, what is the value of dd?

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Cevap: 77

Cevap

The value of dd is 77.
The line 1\ell_1 has equation y=34x3y = \frac{3}{4}x - 3, placing its yy-intercept at (0,3)(0, -3). Line 2\ell_2 is perpendicular, so its slope is 43-\frac{4}{3}, giving the equation y=43x+dy = -\frac{4}{3}x + d. The vertical base of the triangle along the yy-axis spans from (0,3)(0, -3) to (0,d)(0, d), with a length of d+3d + 3. The intersection of the two lines occurs at an xx-coordinate of 12(d+3)25\frac{12(d+3)}{25}, which serves as the height of the triangle. Setting the area 12×(d+3)×12(d+3)25=24\frac{1}{2} \times (d+3) \times \frac{12(d+3)}{25} = 24 simplifies to (d+3)2=100(d+3)^2 = 100. Because d>0d > 0, d+3=10d + 3 = 10, giving d=7d = 7.

Adım Adım Çözüm

1
Find the slope and yy-intercept of line 1\ell_1.
Converting 3x4y=123x - 4y = 12 into slope-intercept form yields y=34x3y = \frac{3}{4}x - 3. The slope of 1\ell_1 is m1=34m_1 = \frac{3}{4} and its yy-intercept is (0,3)(0, -3).
Knowing the slope and yy-intercept of 1\ell_1 is essential to determine the equation of line 2\ell_2 and the vertices of the triangular region along the yy-axis.
2
Determine the equation of line 2\ell_2.
Since 2\ell_2 is perpendicular to 1\ell_1, its slope is the negative reciprocal of 34\frac{3}{4}, which is m2=43m_2 = -\frac{4}{3}. Given that 2\ell_2 intersects the yy-axis at (0,d)(0, d), its equation is y=43x+dy = -\frac{4}{3}x + d.
Perpendicular lines have slopes that are negative reciprocals of each other.
3
Find the xx-coordinate of the intersection point of 1\ell_1 and 2\ell_2.
Set the two equations equal: 34x3=43x+d    (34+43)x=d+3    2512x=d+3    x=12(d+3)25\frac{3}{4}x - 3 = -\frac{4}{3}x + d \implies \left(\frac{3}{4} + \frac{4}{3}\right)x = d + 3 \implies \frac{25}{12}x = d + 3 \implies x = \frac{12(d+3)}{25}.
The xx-coordinate of the intersection point represents the horizontal altitude (height) of the triangle with respect to the vertical base along the yy-axis.
4
Express the area of the triangular region in terms of dd and solve for dd.
The vertical base along the yy-axis stretches from (0,3)(0, -3) to (0,d)(0, d), having length d(3)=d+3d - (-3) = d + 3. The height is h=12(d+3)25h = \frac{12(d+3)}{25}. Using the area formula Area=12×base×height\text{Area} = \frac{1}{2} \times \text{base} \times \text{height}, we set 12(d+3)(12(d+3)25)=24    6(d+3)225=24    (d+3)2=100\frac{1}{2}(d+3)\left(\frac{12(d+3)}{25}\right) = 24 \implies \frac{6(d+3)^2}{25} = 24 \implies (d+3)^2 = 100. Since d>0d > 0, d+3=10d + 3 = 10, so d=7d = 7.
The problem states that the area of the triangle is 2424.

Anahtar Kavram

Perpendicular line slopes and geometric area calculations using coordinate geometry
Tahmini Süre:2m 30s
Soru 1587Soru

A coffee roaster creates a custom blend by combining Grade X beans costing $p\$p per pound with Grade Y beans costing $q\$q per pound, where 0<p<q0 < p < q. The batch contains a total of MM pounds, consisting of xx pounds of Grade X and yy pounds of Grade Y. The total cost of the batch is CC dollars, and the average cost per pound of the blend is AA dollars. Which of the following algebraic relationships MUST be true? Indicate all such statements.

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Cevap: The weight of Grade X beans in pounds is given by x=qMCqpx = \frac{qM - C}{q - p}.; The average cost per pound of the blend satisfies A=qx(qp)MA = q - \frac{x(q - p)}{M}.; The ratio of the weight of Grade X to the weight of Grade Y in the blend is equal to qAAp\frac{q - A}{A - p}.

Cevap

The true statements are that the weight of Grade X beans is x=qMCqpx = \frac{qM - C}{q - p}, the average cost per pound satisfies A=qx(qp)MA = q - \frac{x(q - p)}{M}, and the ratio of Grade X weight to Grade Y weight is qAAp\frac{q - A}{A - p}.
The correct statements correctly model the system of equations x+y=Mx + y = M and C=px+qyC = px + qy. Solving for xx in terms of total cost gives x=qMCqpx = \frac{qM - C}{q - p}. Dividing the expression for total cost by total mass MM yields A=qx(qp)MA = q - \frac{x(q - p)}{M}. Finally, setting total cost C=A(x+y)=px+qyC = A(x+y) = px + qy and rearranging gives the ratio xy=qAAp\frac{x}{y} = \frac{q - A}{A - p}.

Adım Adım Çözüm

1
Set up equations for total mass MM and total cost CC using individual weights xx and yy.
x+y=M    y=Mxx + y = M \implies y = M - x and C=px+qy=px+q(Mx)C = px + qy = px + q(M - x).
Relating the two variables through total weight eliminates yy to express cost purely in terms of xx.
2
Solve the total cost equation for xx.
C=qM(qp)x    (qp)x=qMC    x=qMCqpC = qM - (q - p)x \implies (q - p)x = qM - C \implies x = \frac{qM - C}{q - p}.
Isolating xx confirms the valid algebraic formula for the weight of Grade X.
3
Calculate average cost A=CMA = \frac{C}{M} by substituting the simplified expression for CC.
A=qM(qp)xM=qx(qp)MA = \frac{qM - (q - p)x}{M} = q - \frac{x(q - p)}{M}.
Dividing total cost by total weight MM yields the weighted average cost per pound.
4
Determine the ratio of component weights xy\frac{x}{y} in terms of unit costs p,qp, q and average cost AA.
A(x+y)=px+qy    Ax+Ay=px+qy    y(qA)=x(Ap)    xy=qAApA(x + y) = px + qy \implies Ax + Ay = px + qy \implies y(q - A) = x(A - p) \implies \frac{x}{y} = \frac{q - A}{A - p}.
Rearranging the weighted average equation isolates the ratio of the quantities of the two components.

Anahtar Kavram

Linear weighted averages and multi-variable system modeling in mixture word problems.
Tahmini Süre:2m 30s
Soru 1588Soru

A municipal utility company charges residential customers according to two seasonal rate structures. During the peak summer season, electricity costs $0.24\$0.24 per kilowatt-hour (kWh\text{kWh}). During the off-peak season, electricity costs $0.15\$0.15 per kWh\text{kWh}. A homeowner consumed a total of 14,000 kWh14,000\text{ kWh} of electricity over the entire year, resulting in a total annual bill of $2,640\$2,640. How many kilowatt-hours of electricity did the homeowner consume during the peak summer season?

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Cevap: 6,0006,000

Cevap

6,000 kWh6,000\text{ kWh}
The correct answer of 6,000 kWh6,000\text{ kWh} is found by setting up a linear model for total energy consumption (x+y=14,000x + y = 14,000) and total cost (0.24x+0.15y=2,6400.24x + 0.15y = 2,640). Substituting y=14,000xy = 14,000 - x gives 0.09x=5400.09x = 540, which solves to x=6,000 kWhx = 6,000\text{ kWh}.

Adım Adım Çözüm

1
Define variables for the two seasons.
Let xx be the number of kilowatt-hours consumed during the peak summer season, and let yy be the number of kilowatt-hours consumed during the off-peak season.
Establishing clear variables allows modeling the problem as a system of linear equations.
2
Set up the total consumption equation and express yy in terms of xx.
x+y=14,000    y=14,000xx + y = 14,000 \implies y = 14,000 - x
The total consumption across both seasons equals 14,000 kWh14,000\text{ kWh}.
3
Set up the total cost equation using the respective seasonal rates.
0.24x+0.15y=2,6400.24x + 0.15y = 2,640
Peak electricity costs $0.24/kWh\$0.24/\text{kWh} and off-peak costs $0.15/kWh\$0.15/\text{kWh}, summing to the total annual cost of $2,640\$2,640.
4
Substitute y=14,000xy = 14,000 - x into the cost equation and solve for xx.
0.24x+0.15(14,000x)=2,640    0.24x+2,1000.15x=2,640    0.09x=540    x=6,0000.24x + 0.15(14,000 - x) = 2,640 \implies 0.24x + 2,100 - 0.15x = 2,640 \implies 0.09x = 540 \implies x = 6,000
Simplifying the single-variable linear equation isolates the peak season consumption.

Anahtar Kavram

Linear Modeling and Systems of Linear Equations
Tahmini Süre:1m 30s
Soru 1589Soru

In the xyxy-plane, line kk passes through the origin (0,0)(0,0) and the point (4,3)(4, 3). Line mm is perpendicular to line kk and intersects line kk at point (4,3)(4, 3). If line mm intersects the xx-axis at point QQ and the yy-axis at point RR, what is the distance between point QQ and point RR?

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Cevap: 12512\frac{125}{12}

Cevap

12512\frac{125}{12}
The correct answer is derived by finding the slope of line kk as 34\frac{3}{4}, taking its negative reciprocal 43-\frac{4}{3} as the slope of perpendicular line mm, using the point (4,3)(4,3) to form line mm's equation y=43x+253y = -\frac{4}{3}x + \frac{25}{3}, identifying intercepts Q(254,0)Q\left(\frac{25}{4}, 0\right) and R(0,253)R\left(0, \frac{25}{3}\right), and applying the distance formula to obtain (254)2+(253)2=12512\sqrt{\left(\frac{25}{4}\right)^2 + \left(\frac{25}{3}\right)^2} = \frac{125}{12}.

Adım Adım Çözüm

1
Determine the slope of line kk
The slope of line kk is mk=3040=34m_k = \frac{3 - 0}{4 - 0} = \frac{3}{4}.
The slope of a line passing through (x1,y1)(x_1, y_1) and (x2,y2)(x_2, y_2) is given by y2y1x2x1\frac{y_2 - y_1}{x_2 - x_1}.
2
Find the equation of line mm
Line mm has slope mm=43m_m = -\frac{4}{3} and equation y3=43(x4)    y=43x+253y - 3 = -\frac{4}{3}(x - 4) \implies y = -\frac{4}{3}x + \frac{25}{3}.
Perpendicular lines have slopes that are negative reciprocals of each other (mm=1mkm_m = -\frac{1}{m_k}). Point-slope form is used with point (4,3)(4, 3).
3
Calculate the intercepts QQ and RR
xx-intercept Q=(254,0)Q = \left(\frac{25}{4}, 0\right) and yy-intercept R=(0,253)R = \left(0, \frac{25}{3}\right).
Setting y=0y = 0 in y=43x+253y = -\frac{4}{3}x + \frac{25}{3} gives x=254x = \frac{25}{4}. Setting x=0x = 0 gives y=253y = \frac{25}{3}.
4
Compute the distance between QQ and RR
Distance d=(254)2+(253)2=25116+19=2525144=25×512=12512d = \sqrt{\left(\frac{25}{4}\right)^2 + \left(\frac{25}{3}\right)^2} = 25 \sqrt{\frac{1}{16} + \frac{1}{9}} = 25 \sqrt{\frac{25}{144}} = 25 \times \frac{5}{12} = \frac{125}{12}.
Applying the distance formula d=(x2x1)2+(y2y1)2d = \sqrt{(x_2 - x_1)^2 + (y_2 - y_1)^2} for points QQ and RR.

Anahtar Kavram

Perpendicular slopes and distance formula in coordinate geometry
Tahmini Süre:2m 0s
Soru 1590Soru

Dataset WW consists of 101101 distinct real numbers arranged in strictly increasing order: x1<x2<<x101x_1 < x_2 < \dots < x_{101}. The interquartile range of WW is QQ, its range is RR, and its standard deviation is σ\sigma. A new dataset WW' is constructed by adding a positive constant kk to each of the highest 2525 observations (that is, x77,x78,,x101x_{77}, x_{78}, \dots, x_{101} become x77+k,x78+k,,x101+kx_{77}+k, x_{78}+k, \dots, x_{101}+k), while the first 7676 observations remain unchanged. Which of the following statements MUST be true regarding the statistics of WW' compared to dataset WW?

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Cevap: The interquartile range of WW' is equal to Q+k2Q + \frac{k}{2}.

Cevap

The statement specifying that the interquartile range of WW' is equal to Q+k2Q + \frac{k}{2} must be true.
For an ordered dataset of 101 elements, the first quartile Q1Q_1 is the median of the lower 50 values (x25+x262\frac{x_{25} + x_{26}}{2}) and the third quartile Q3Q_3 is the median of the upper 50 values (x76+x772\frac{x_{76} + x_{77}}{2}). Since elements x1x_1 through x76x_{76} are unchanged, Q1Q_1 remains identical. However, x77x_{77} increases by kk, causing Q3Q_3 to increase by k2\frac{k}{2}. Consequently, the new interquartile range is Q=Q3Q1=Q+k2Q' = Q_3' - Q_1' = Q + \frac{k}{2}.

Adım Adım Çözüm

1
Determine the position of quartiles for a 101-element dataset.
For 101101 sorted values, the median is x51x_{51}. The lower half consists of 5050 values (x1x_1 through x50x_{50}), whose median Q1Q_1 is x25+x262\frac{x_{25} + x_{26}}{2}. The upper half consists of 5050 values (x52x_{52} through x101x_{101}), whose median Q3Q_3 is x76+x772\frac{x_{76} + x_{77}}{2}.
Establishing the exact index formulas for Q1Q_1 and Q3Q_3 is required to evaluate changes in IQR.
2
Analyze how Q1Q_1 changes in dataset WW'.
x25x_{25} and x26x_{26} are among the first 7676 observations, so they are unchanged. Thus, Q1=Q1Q_1' = Q_1.
Since the modified values start at index 77, the first quartile remains completely unaffected.
3
Analyze how Q3Q_3 changes in dataset WW'.
In WW', x76=x76x_{76}' = x_{76} and x77=x77+kx_{77}' = x_{77} + k. Therefore, Q3=x76+(x77+k)2=x76+x772+k2=Q3+k2Q_3' = \frac{x_{76} + (x_{77} + k)}{2} = \frac{x_{76} + x_{77}}{2} + \frac{k}{2} = Q_3 + \frac{k}{2}.
One of the two values used to calculate Q3Q_3 is shifted by kk, so their average increases by k2\frac{k}{2}.
4
Compute the new interquartile range QQ'.
Q=Q3Q1=(Q3+k2)Q1=(Q3Q1)+k2=Q+k2Q' = Q_3' - Q_1' = \left(Q_3 + \frac{k}{2}\right) - Q_1 = (Q_3 - Q_1) + \frac{k}{2} = Q + \frac{k}{2}.
Subtracting Q1Q_1' from Q3Q_3' yields the new interquartile range directly.

Anahtar Kavram

Quartile Interpolation and Selective Data Transformations
Soru 1591Soru

The quadratic equation x2px+q=0x^2 - px + q = 0, where pp and qq are real constants with p>0p > 0, has two real roots r1r_1 and r2r_2. If r12+r22=29r_1^2 + r_2^2 = 29 and r13+r23=117r_1^3 + r_2^3 = 117, what is the value of qq?

Cevabı ve açıklamayı göster

Cevap: -10

Cevap

The value of qq is 10-10.
By Vieta's formulas, r1+r2=pr_1 + r_2 = p and r1r2=qr_1 r_2 = q. Using the identity r12+r22=(r1+r2)22r1r2=29r_1^2 + r_2^2 = (r_1 + r_2)^2 - 2r_1 r_2 = 29, we get q=p2292q = \frac{p^2 - 29}{2}. Using the sum of cubes identity r13+r23=(r1+r2)(r12r1r2+r22)=117r_1^3 + r_2^3 = (r_1 + r_2)(r_1^2 - r_1 r_2 + r_2^2) = 117, we obtain p(29q)=117p(29 - q) = 117. Substituting qq into this equation yields p387p+234=0p^3 - 87p + 234 = 0. Factoring this cubic equation yields p=3p = 3 as a valid root, leading to q=10q = -10. Evaluating the discriminant p24q=94(10)=49>0p^2 - 4q = 9 - 4(-10) = 49 > 0 confirms that real roots exist. The second positive root for pp gives a negative discriminant, making 10-10 the unique correct value of qq.

Adım Adım Çözüm

1
Express symmetric sums of roots in terms of equation coefficients pp and qq using Vieta's formulas.
r1+r2=pr_1 + r_2 = p and r1r2=qr_1 r_2 = q. Therefore, r12+r22=(r1+r2)22r1r2=p22q=29r_1^2 + r_2^2 = (r_1 + r_2)^2 - 2r_1 r_2 = p^2 - 2q = 29, which gives q=p2292q = \frac{p^2 - 29}{2}.
Relating root sums and products directly to coefficients simplifies the algebraic system.
2
Express the sum of cubes in terms of pp and qq and substitute qq.
r13+r23=(r1+r2)(r12r1r2+r22)=p(29q)=117r_1^3 + r_2^3 = (r_1 + r_2)(r_1^2 - r_1 r_2 + r_2^2) = p(29 - q) = 117. Substituting q=p2292q = \frac{p^2 - 29}{2} yields p(29p2292)=117    p(87p2)=234    p387p+234=0p\left(29 - \frac{p^2 - 29}{2}\right) = 117 \implies p(87 - p^2) = 234 \implies p^3 - 87p + 234 = 0.
Combining symmetric expressions forms a single polynomial equation in variable pp.
3
Factor the cubic equation p387p+234=0p^3 - 87p + 234 = 0 to find candidate values for p>0p > 0.
Testing factor p=3p = 3 gives 3387(3)+234=27261+234=03^3 - 87(3) + 234 = 27 - 261 + 234 = 0. Factoring out (p3)(p - 3) gives (p3)(p2+3p78)=0(p - 3)(p^2 + 3p - 78) = 0.
Finding the roots of the polynomial identifies candidate values for coefficient pp.
4
Verify the real root constraint p24q>0p^2 - 4q > 0 for candidates of pp.
For p=3p = 3, q=32292=10q = \frac{3^2 - 29}{2} = -10, giving discriminant p24q=94(10)=49>0p^2 - 4q = 9 - 4(-10) = 49 > 0 (real roots 55 and 2-2). For the positive root p=321327.458p = \frac{\sqrt{321}-3}{2} \approx 7.458 of p2+3p78=0p^2 + 3p - 78 = 0, the discriminant is p24q=3p296.63<0p^2 - 4q = 3p - 29 \approx -6.63 < 0, which yields non-real complex roots.
The question specifies real roots, so candidate solutions resulting in negative discriminants must be discarded.

Anahtar Kavram

Quadratic Equations and Factoring (Vieta's Formulas, Symmetric Polynomials, and Real Root Conditions)
Soru 1592Soru

An altitude of an acute triangle divides its base into two adjacent segments of lengths 55 and 99. If the area of the triangle is 8484 square units, what is the perimeter of the triangle?

Cevabı ve açıklamayı göster

Cevap: 4242

Cevap

The perimeter of the triangle is 4242.
The base of the triangle is the sum of the two adjacent segments, 5+9=145 + 9 = 14. Setting up the area formula gives 84=12×14×h84 = \frac{1}{2} \times 14 \times h, which yields an altitude height of h=12h = 12. The altitude creates two right triangles: one with legs 55 and 1212 (hypotenuse 52+122=13\sqrt{5^2 + 12^2} = 13) and another with legs 99 and 1212 (hypotenuse 92+122=15\sqrt{9^2 + 12^2} = 15). Adding all three side lengths (14+13+1514 + 13 + 15) yields 4242.

Adım Adım Çözüm

1
Find the total base length and calculate the height (altitude) of the triangle.
Base =5+9=14= 5 + 9 = 14. Height h=2×Areabase=2×8414=12h = \frac{2 \times \text{Area}}{\text{base}} = \frac{2 \times 84}{14} = 12.
The area of a triangle is given by A=12bhA = \frac{1}{2} b h.
2
Calculate the lengths of the two non-base sides using the Pythagorean theorem on the two right triangles formed by the altitude.
Left side =52+122=25+144=13= \sqrt{5^2 + 12^2} = \sqrt{25 + 144} = 13. Right side =92+122=81+144=15= \sqrt{9^2 + 12^2} = \sqrt{81 + 144} = 15.
An altitude drawn to the base creates two right triangles sharing the altitude as a common leg.
3
Sum all three boundary sides to find the perimeter.
Perimeter =14+13+15=42= 14 + 13 + 15 = 42.
Perimeter is the total length around the outside of the triangle.

Anahtar Kavram

Area and perimeter of triangles split by an altitude using the Pythagorean theorem.
Tahmini Süre:1m 30s
Soru 1593Soru

The running times, in minutes, for a fleet of delivery vehicles have a 25th percentile of 134134 minutes and a 75th percentile of 242242 minutes. To analyze the data in hours, a manager converts each vehicle's running time to hours by dividing by 6060 and then adds a fixed delay of 1.251.25 hours to every converted value. What is the interquartile range, in hours, of the adjusted running times?

Cevabı ve açıklamayı göster

Cevap: 1.8

Cevap

The interquartile range of the adjusted running times is 1.8 hours.
The interquartile range (IQR) measures the spread of the middle 50% of a dataset (Q3Q1Q_3 - Q_1). For the original dataset in minutes, IQR=242134=108IQR = 242 - 134 = 108 minutes. When data is transformed linearly via Y=aX+bY = aX + b, scaling all values by a positive constant aa scales the IQR by aa, whereas adding a constant bb shifts all values equally and does not change the distance between percentiles. Here a=160a = \frac{1}{60} and b=1.25b = 1.25. Therefore, the new IQR in hours is 108×160=1.8108 \times \frac{1}{60} = 1.8 hours.

Adım Adım Çözüm

1
Find the original interquartile range (IQR) in minutes
IQR = 242 - 134 = 108 minutes
The interquartile range is defined as the difference between the 75th percentile (Q3) and the 25th percentile (Q1).
2
Apply the scaling factor for unit conversion
108 / 60 = 1.8 hours
Dividing every value by 60 scales the data by a factor of 1/60, which scales measures of dispersion like IQR by |1/60|.
3
Evaluate the effect of adding the constant shift
Adjusted IQR remains 1.8 hours
Adding a constant shift to every data point shifts the entire distribution without changing the spread or distance between percentiles.

Anahtar Kavram

Linear Transformations on Measures of Dispersion
Soru 1594Soru

Three adjacent faces of a right rectangular prism have surface areas of 2424, 3636, and 5454 square centimeters. What is the volume of the prism, in cubic centimeters?

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Cevap: 216

Cevap

The volume of the rectangular prism is 216216 cubic centimeters.
Let the edge lengths of the right rectangular prism be ll, ww, and hh. The areas of three adjacent faces meeting at a common vertex are given by lw=24lw = 24, wh=36wh = 36, and lh=54lh = 54. Multiplying these three equations together yields (lw)(wh)(lh)=(lwh)2=24×36×54=46,656(lw)(wh)(lh) = (lwh)^2 = 24 \times 36 \times 54 = 46,656. Since the volume VV of a right rectangular prism is equal to lwhlwh, taking the positive square root gives V=46,656=216V = \sqrt{46,656} = 216 cubic centimeters.

Adım Adım Çözüm

1
Define variables for the three dimensions of the rectangular prism.
Let ll, ww, and hh represent the length, width, and height of the prism.
The area of each rectangular face is the product of two adjacent dimensions.
2
Express the given face areas in terms of the dimensions.
lw=24lw = 24, wh=36wh = 36, and lh=54lh = 54.
Adjacent faces share pairwise dimensions.
3
Multiply all three face area equations together.
(lw)(wh)(lh)=l2w2h2=(lwh)2=24×36×54=46,656(lw)(wh)(lh) = l^2 w^2 h^2 = (lwh)^2 = 24 \times 36 \times 54 = 46,656.
Multiplying the three face areas yields the square of the prism's volume (V=lwhV = lwh).
4
Calculate the square root of the product to determine the volume.
V=lwh=46,656=216V = lwh = \sqrt{46,656} = 216.
Taking the square root gives the volume directly without needing to solve for individual edge lengths.

Anahtar Kavram

For a right rectangular prism with adjacent face areas A1A_1, A2A_2, and A3A_3, the volume is given by V=A1×A2×A3V = \sqrt{A_1 \times A_2 \times A_3}.
Tahmini Süre:1m 15s
Soru 1595Soru

Group A consists of 1515 test scores with an arithmetic mean of 8080 and a median of 8282. Group B consists of 2525 test scores with an arithmetic mean of 9090 and a median of 8686. The two groups are combined into a single dataset of 4040 test scores. Which of the following statements MUST be true about the combined dataset? Indicate all such statements.

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Cevabı ve açıklamayı göster

Cevap: The mean of the combined dataset is equal to 86.2586.25.; The median of the combined dataset is at least 8282.; The median of the combined dataset is at most 8686.

Cevap

The statements asserting that the combined mean is 86.2586.25, that the combined median is at least 8282, and that the combined median is at most 8686 must all be true.
The combined mean is calculated directly from the total sum divided by total elements, giving exactly 86.2586.25. For the median of 4040 combined values (the average of the 20th20\text{th} and 21st21\text{st} values in sorted order), counting how many values are guaranteed to be above or below specific thresholds shows that at least 2121 values are 82\ge 82 and at least 2121 values are 86\le 86. Therefore, the median must lie within [82,86][82, 86].

Adım Adım Çözüm

1
Calculate the weighted arithmetic mean for the combined dataset.
Combined Mean = 15×80+25×9015+25=1200+225040=345040=86.25\frac{15 \times 80 + 25 \times 90}{15 + 25} = \frac{1200 + 2250}{40} = \frac{3450}{40} = 86.25.
The mean of combined sets is the total sum of all values divided by the total number of items.
2
Analyze the lower bound for the median of the combined set.
At least 2121 values in the combined set of 4040 items are greater than or equal to 8282.
Since the median of Group A (1515 items) is 8282, at least 88 items are 82\ge 82. Since the median of Group B (2525 items) is 8686, at least 1313 items are 8682\ge 86 \ge 82. In total, 8+13=218 + 13 = 21 items are 82\ge 82. In a sorted list of 4040 items, having at least 2121 items 82\ge 82 implies that the 20th20\text{th} and 21st21\text{st} items must be 82\ge 82, so the median 82\ge 82.
3
Analyze the upper bound for the median of the combined set.
At least 2121 values in the combined set of 4040 items are less than or equal to 8686.
Group A has at least 88 items 8286\le 82 \le 86. Group B has at least 1313 items 86\le 86. Thus, at least 8+13=218 + 13 = 21 items are 86\le 86. In a sorted list of 4040 items, having at least 2121 items 86\le 86 ensures the 20th20\text{th} and 21st21\text{st} items are 86\le 86, so the median 86\le 86.
4
Evaluate the remaining statements regarding the exact median and mode.
Neither the exact median value of 8484 nor the existence/location of a mode is guaranteed.
Medians do not combine linearly like means, and mode depends entirely on specific frequency counts which are not given.

Anahtar Kavram

Weighted averages and order statistic bounds for combined datasets
Soru 1596Soru

For all real numbers xx, the function ff is defined by f(x)=x24x+7f(x) = x^2 - 4x + 7 and the function gg is defined by g(x)=2x+1g(x) = 2x + 1. If f(g(k))=19f(g(k)) = 19 and k<0k < 0, what is the value of kk?

Cevabı ve açıklamayı göster

Cevap: -1.5

Cevap

The value of kk is 1.5-1.5.
To solve for kk, substitute g(k)=2k+1g(k) = 2k + 1 into f(x)f(x) to get f(g(k))=(2k+1)24(2k+1)+7f(g(k)) = (2k + 1)^2 - 4(2k + 1) + 7. Expanding and combining like terms yields 4k24k+44k^2 - 4k + 4. Setting this equal to 1919 gives 4k24k15=04k^2 - 4k - 15 = 0. Factoring the quadratic expression yields (2k5)(2k+3)=0(2k - 5)(2k + 3) = 0, which gives k=52=2.5k = \frac{5}{2} = 2.5 or k=32=1.5k = -\frac{3}{2} = -1.5. Since the problem specifies that k<0k < 0, the value of kk must be 1.5-1.5.

Adım Adım Çözüm

1
Express the nested composite function f(g(k))f(g(k)) in terms of kk
f(g(k))=(2k+1)24(2k+1)+7f(g(k)) = (2k + 1)^2 - 4(2k + 1) + 7
Substituting g(k)=2k+1g(k) = 2k + 1 for every occurrence of xx in f(x)f(x) sets up the composite function evaluation.
2
Expand terms and simplify the algebraic expression
f(g(k))=4k24k+4f(g(k)) = 4k^2 - 4k + 4
Expanding (2k+1)2=4k2+4k+1(2k + 1)^2 = 4k^2 + 4k + 1 and distributing 4(2k+1)=8k4-4(2k + 1) = -8k - 4, then combining like terms yields 4k24k+44k^2 - 4k + 4.
3
Set the composite function expression equal to 19 and form a standard quadratic equation
4k24k15=04k^2 - 4k - 15 = 0
Subtracting 1919 from both sides produces a standard quadratic equation ax2+bx+c=0ax^2 + bx + c = 0.
4
Solve the quadratic equation and apply the condition k<0k < 0
k=1.5k = -1.5
Factoring (2k5)(2k+3)=0(2k - 5)(2k + 3) = 0 gives k=2.5k = 2.5 or k=1.5k = -1.5. The constraint k<0k < 0 selects k=1.5k = -1.5.

Anahtar Kavram

Composite function evaluation f(g(x))f(g(x)) combined with quadratic equation solving under domain constraints.
Soru 1597Soru

A total of 120 software engineers at a firm were surveyed about their attendance at three professional development workshops: Machine Learning (MM), Cloud Computing (CC), and Cybersecurity (SS). The survey results revealed the following:

- 65 engineers attended Machine Learning
- 55 engineers attended Cloud Computing
- 48 engineers attended Cybersecurity
- 25 engineers attended both Machine Learning and Cloud Computing
- 18 engineers attended both Cloud Computing and Cybersecurity
- 20 engineers attended both Machine Learning and Cybersecurity
- 10 engineers attended all three workshops

How many of the surveyed software engineers attended exactly one of the three workshops?

Cevabı ve açıklamayı göster

Cevap: 72

Cevap

72 engineers attended exactly one of the three workshops.
To find the number of engineers attending exactly one workshop, calculate the exclusive single-set counts for each category using a 3-set Venn diagram model. Subtracting the overlapping regions gives 30 for Machine Learning only, 22 for Cloud Computing only, and 20 for Cybersecurity only. Summing these exclusive regions yields 30+22+20=7230 + 22 + 20 = 72. Alternatively, using the algebraic formula Exactly 1=(M+C+S)2(MC+CS+MS)+3MCS=(65+55+48)2(25+18+20)+3(10)=168126+30=72|\text{Exactly 1}| = (|M| + |C| + |S|) - 2(|M \cap C| + |C \cap S| + |M \cap S|) + 3|M \cap C \cap S| = (65 + 55 + 48) - 2(25 + 18 + 20) + 3(10) = 168 - 126 + 30 = 72.

Adım Adım Çözüm

1
Find the number of engineers in the regions corresponding to exactly two workshops.
Machine Learning and Cloud Computing only = 2510=1525 - 10 = 15; Cloud Computing and Cybersecurity only = 1810=818 - 10 = 8; Machine Learning and Cybersecurity only = 2010=1020 - 10 = 10.
The given pairwise intersection values include engineers who attended all three workshops.
2
Calculate the number of engineers who attended only one specific workshop.
Machine Learning only = 65(15+10+10)=3065 - (15 + 10 + 10) = 30; Cloud Computing only = 55(15+8+10)=2255 - (15 + 8 + 10) = 22; Cybersecurity only = 48(10+8+10)=2048 - (10 + 8 + 10) = 20.
Subtract all overlapping regions (two-workshop-only and three-workshop) from each set's total.
3
Sum the single-workshop regions to find the total attending exactly one workshop.
30+22+20=7230 + 22 + 20 = 72.
The subsets representing single workshop attendance are disjoint.

Anahtar Kavram

Principle of Inclusion-Exclusion for Three Sets and Venn Diagram Region Partitioning
Tahmini Süre:2m 0s
Soru 1598Soru

An industrial facility has three supply pipes—Pipe A, Pipe B, and Pipe C—that can fill a storage reservoir. Pipe A operating alone can fill the empty reservoir in aa hours. Pipe B operating alone takes 50%50\% longer than Pipe A to fill the empty reservoir. Pipe C operating alone fills the empty reservoir at a rate equal to the combined filling rate of Pipe A and Pipe B.

Initially, the reservoir is empty. Pipe A and Pipe B are opened simultaneously. After 22 hours, Pipe B is closed and Pipe C is opened, while Pipe A remains open. The reservoir becomes completely full exactly 44 hours after Pipe A and Pipe B were initially opened.

Which of the following statements must be true? Select all such statements.

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Cevabı ve açıklamayı göster

Cevap: Pipe A operating alone would fill the empty reservoir in 88 hours and 4040 minutes.; During the first 22 hours of the process, exactly 513\frac{5}{13} of the total capacity of the reservoir is filled.; Pipe C operating alone would fill the empty reservoir in 55 hours and 1212 minutes.

Cevap

The statements asserting that Pipe A operating alone takes 8 hours and 40 minutes, that 5/13 of the capacity is filled in the first 2 hours, and that Pipe C operating alone takes 5 hours and 12 minutes are all true.
Using the rate relationships RA=1aR_A = \frac{1}{a}, RB=23aR_B = \frac{2}{3a}, and RC=53aR_C = \frac{5}{3a}, the equation 2(RA+RB)+2(RA+RC)=12(R_A + R_B) + 2(R_A + R_C) = 1 simplifies to 263a=1\frac{26}{3a} = 1, giving a=263a = \frac{26}{3} hours. This verifies that Pipe A takes 8 hours 40 minutes alone, Phase 1 fills 5/13 of the reservoir capacity, and Pipe C takes 5.2 hours (5 hours 12 minutes) alone.

Adım Adım Çözüm

1
Express the individual work rates of Pipe A, Pipe B, and Pipe C in terms of parameter aa.
RA=1aR_A = \frac{1}{a}, RB=11.5a=23aR_B = \frac{1}{1.5a} = \frac{2}{3a}, and RC=RA+RB=1a+23a=53aR_C = R_A + R_B = \frac{1}{a} + \frac{2}{3a} = \frac{5}{3a}.
Work rate is defined as the reciprocal of the time required to complete one unit of work.
2
Formulate an equation for total work completed over the two 2-hour phases.
2(RA+RB)+2(RA+RC)=1    2(53a)+2(83a)=1    103a+163a=12(R_A + R_B) + 2(R_A + R_C) = 1 \implies 2\left(\frac{5}{3a}\right) + 2\left(\frac{8}{3a}\right) = 1 \implies \frac{10}{3a} + \frac{16}{3a} = 1.
Pipes A and B operate for the first 2 hours, followed by Pipes A and C operating for the next 2 hours to complete 1 full reservoir.
3
Solve the work equation for aa and determine Pipe A's solo time.
\frac{26}{3a} = 1 \implies a = \frac{26}{3} = 8\frac{2}{3} \text{ hours} = 8 \text{ hours } 40 \text{ minutes}.
Fractional hours are converted to minutes by multiplying 23\frac{2}{3} by 6060.
4
Evaluate the volume filled in Phase 1 and the solo filling time for Pipe C.
\text{Phase 1 volume} = \frac{10}{3(26/3)} = \frac{5}{13}. \text{ Pipe C solo time} = \frac{1}{R_C} = \frac{3a}{5} = \frac{26}{5} = 5.2 \text{ hours} = 5 \text{ hours } 12 \text{ minutes}.
Substituting a=263a = \frac{26}{3} into the respective rate expressions yields the exact time and volume parameters.

Anahtar Kavram

Formulating combined rate models and solving sequential multi-stage work problems.
Soru 1599Soru

A health club surveyed 100100 members regarding their use of cardio machines and weight equipment. Of the members surveyed, 6060 use cardio machines, 5050 use weight equipment, and 1515 use neither cardio machines nor weight equipment. Which of the following statements must be true? Indicate all such statements.

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Cevabı ve açıklamayı göster

Cevap: Exactly 2525 members use both cardio machines and weight equipment.; Exactly 3535 members use cardio machines but do not use weight equipment.; Exactly 8585 members use at least one of the two types of equipment.

Cevap

The true statements are those stating that exactly 25 members use both types of equipment, exactly 35 members use cardio machines only, and exactly 85 members use at least one type of equipment.
The total surveyed population of 100100 consists of members using at least one type of equipment and members using neither (1515). Thus, 10015=85100 - 15 = 85 members use at least one type of equipment. Using the inclusion-exclusion formula Union=Cardio+WeightsIntersection\text{Union} = \text{Cardio} + \text{Weights} - \text{Intersection}, we have 85=60+50Intersection85 = 60 + 50 - \text{Intersection}, giving an intersection of 2525 members using both types of equipment. Subtracting 2525 from the 6060 total cardio users shows that 3535 members use cardio machines exclusively.

Adım Adım Çözüm

1
Calculate the total number of members using at least one type of equipment.
Total using at least one type =10015=85= 100 - 15 = 85.
Members using at least one type of equipment represent the total surveyed population minus those who use neither.
2
Calculate the number of members using both cardio machines and weight equipment using the principle of inclusion-exclusion.
Both=Cardio+WeightsAt least one=60+5085=25\text{Both} = \text{Cardio} + \text{Weights} - \text{At least one} = 60 + 50 - 85 = 25.
Adding the individual set counts double-counts the overlapping region, so subtracting the total union gives the intersection size.
3
Calculate the number of members using cardio machines only.
Cardio Only=CardioBoth=6025=35\text{Cardio Only} = \text{Cardio} - \text{Both} = 60 - 25 = 35.
Subtracting the intersection from the total cardio group yields the exclusive cardio users.

Anahtar Kavram

Principle of Inclusion-Exclusion for Two Sets
Tahmini Süre:1m 15s
Soru 1600Soru

In right triangle ABCABC, the measure of angle CC is 9090^\circ. Point DD lies on segment ACAC such that AD=11AD = 11 and BD=13BD = 13. If DC=5DC = 5, what is the perimeter of triangle ABDABD?

Cevabı ve açıklamayı göster

Cevap: 44

Cevap

The perimeter of triangle ABDABD is 4444.
To find the perimeter of triangle ABDABD, we need the lengths of its three sides: ADAD, BDBD, and ABAB. We are given AD=11AD = 11 and BD=13BD = 13. To find ABAB, we first analyze right triangle BCDBCD with right angle at CC, hypotenuse BD=13BD = 13, and leg DC=5DC = 5. Using the Pythagorean theorem, leg BC=13252=12BC = \sqrt{13^2 - 5^2} = 12. Next, the full leg AC=AD+DC=11+5=16AC = AD + DC = 11 + 5 = 16. In right triangle ABCABC, legs are AC=16AC = 16 and BC=12BC = 12, making hypotenuse AB=162+122=20AB = \sqrt{16^2 + 12^2} = 20. Finally, the perimeter of triangle ABDABD is 11+13+20=4411 + 13 + 20 = 44.

Adım Adım Çözüm

1
Find the length of side BCBC using right triangle BCDBCD
BC=12BC = 12
In right triangle BCDBCD, angle C=90C = 90^\circ, hypotenuse BD=13BD = 13, and leg DC=5DC = 5. By the Pythagorean theorem, BC=13252=144=12BC = \sqrt{13^2 - 5^2} = \sqrt{144} = 12.
2
Determine the total length of side ACAC
AC=16AC = 16
Since point DD lies on segment ACAC, AC=AD+DC=11+5=16AC = AD + DC = 11 + 5 = 16.
3
Calculate the hypotenuse ABAB of the main right triangle ABCABC
AB=20AB = 20
In right triangle ABCABC, legs are AC=16AC = 16 and BC=12BC = 12. By the Pythagorean theorem, AB=162+122=256+144=400=20AB = \sqrt{16^2 + 12^2} = \sqrt{256 + 144} = \sqrt{400} = 20.
4
Calculate the perimeter of triangle ABDABD
Perimeter =44= 44
The sides of triangle ABDABD are AD=11AD = 11, BD=13BD = 13, and AB=20AB = 20. Adding these gives 11+13+20=4411 + 13 + 20 = 44.

Anahtar Kavram

Pythagorean Theorem and Multi-Step Triangle Properties
ÖncekiSayfa 80 / 107Sonraki
Tüm alıştırma soruları — GRE General Test | Examkin