Tüm alıştırma soruları

2789 soru

Soru 2041Soru

A right circular cylinder has a height of 12 centimeters12\text{ centimeters}. If the total surface area of the cylinder is 170π square centimeters170\pi\text{ square centimeters}, what is the volume, in cubic centimeters, of the cylinder?

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Cevap: 300π300\pi

Cevap

The volume of the cylinder is 300π300\pi cubic centimeters.
The correct answer is the volume of 300π300\pi cubic centimeters. We find this by using the cylinder's surface area equation 2πrh+2πr2=170π2\pi r h + 2\pi r^2 = 170\pi with h=12h = 12, which reduces to r2+12r85=0r^2 + 12r - 85 = 0. Factoring this equation gives the radius r=5r = 5. Plugging r=5r = 5 and h=12h = 12 into the volume formula V=πr2hV = \pi r^2 h gives 300π300\pi.

Adım Adım Çözüm

1
Set up the formula for the total surface area of a cylinder and plug in the given values.
2πrh+2πr2=170π2\pi r h + 2\pi r^2 = 170\pi, where h=12h = 12. This simplifies to 2πr(12)+2πr2=170π2\pi r(12) + 2\pi r^2 = 170\pi, or 24πr+2πr2=170π24\pi r + 2\pi r^2 = 170\pi.
We need to find the radius of the cylinder to calculate its volume.
2
Divide the entire equation by 2π2\pi to simplify it into a standard quadratic form.
r2+12r85=0r^2 + 12r - 85 = 0.
Simplifying the equation makes it easier to solve for the radius rr.
3
Factor the quadratic equation to find the positive value of the radius rr.
(r+17)(r5)=0(r + 17)(r - 5) = 0, which gives r=5r = 5 since the radius must be positive (r>0r > 0).
Factoring allows us to solve for the variable rr.
4
Use the radius r=5r = 5 and height h=12h = 12 to compute the volume of the cylinder.
V=πr2h=π(52)(12)=25×12π=300πV = \pi r^2 h = \pi (5^2)(12) = 25 \times 12 \pi = 300\pi cubic centimeters.
The volume formula for a cylinder is V=πr2hV = \pi r^2 h.

Anahtar Kavram

Calculating volume from total surface area for a cylinder by solving a quadratic relation.
Soru 2042Soru

What is the solution set for the inequality 52(3x1)4x+115 - 2(3x - 1) \geq -4x + 11?

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Cevap: x2x \leq -2

Cevap

The correct solution is xx is less than or equal to 2-2.
To solve the inequality, first distribute the negative two to the terms inside the parentheses to get 56x+24x+115 - 6x + 2 \geq -4x + 11. Combining the constants on the left side yields 76x4x+117 - 6x \geq -4x + 11. Adding four xx to both sides results in 72x117 - 2x \geq 11, and subtracting seven from both sides isolates the variable term, giving 2x4-2x \geq 4. Dividing both sides by negative two and reversing the inequality sign yields the correct solution, xx is less than or equal to negative two.

Adım Adım Çözüm

1
Distribute the 2-2 to the terms inside the parentheses.
56x+24x+115 - 6x + 2 \geq -4x + 11
To simplify the expression by removing the parentheses.
2
Combine the constant terms on the left side of the inequality.
76x4x+117 - 6x \geq -4x + 11
To group like terms together before isolating the variable.
3
Add 4x4x to both sides of the inequality.
72x117 - 2x \geq 11
To move all variable terms to one side of the inequality.
4
Subtract 77 from both sides of the inequality.
2x4-2x \geq 4
To isolate the variable term.
5
Divide both sides by 2-2 and reverse the inequality sign.
x2x \leq -2
Dividing an inequality by a negative number requires reversing the direction of the inequality sign to keep the statement true.

Anahtar Kavram

Solving linear inequalities in one variable using the distributive property and applying the sign reversal rule when dividing by a negative number.
Tahmini Süre:1m 30s
Soru 2043Soru

The mass of a sample of a chemical compound in a reaction decays exponentially. The mass, in grams, of the sample tt hours after the reaction starts can be modeled by the function M(t)=abtM(t) = a \cdot b^t, where aa and bb are positive constants. If the mass of the sample is 1818 grams after 22 hours and 88 grams after 44 hours, what is the initial mass, in grams, of the sample?

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Cevap: 40.5

Cevap

40.5
The initial mass of the sample is 40.540.5 grams (which can also be entered as the fraction 81/281/2). This is found by setting up the two equations from the given points: ab2=18a \cdot b^2 = 18 and ab4=8a \cdot b^4 = 8. Dividing the second equation by the first eliminates aa and gives b2=49b^2 = \frac{4}{9}. Substituting b2=49b^2 = \frac{4}{9} back into the first equation yields a49=18a \cdot \frac{4}{9} = 18. Multiplying both sides by 94\frac{9}{4} results in a=40.5a = 40.5. Since M(0)=ab0=aM(0) = a \cdot b^0 = a, the initial mass of the sample is 40.540.5 grams.

Adım Adım Çözüm

1
Set up the system of exponential equations using the given coordinates.
ab2=18a \cdot b^2 = 18 and ab4=8a \cdot b^4 = 8
This represents the mass of the sample at t=2t = 2 and t=4t = 4 using the model M(t)=abtM(t) = a \cdot b^t.
2
Divide the second equation by the first equation to eliminate the constant aa and solve for b2b^2.
b2=49b^2 = \frac{4}{9}
Dividing the equations yields ab4ab2=818\frac{a \cdot b^4}{a \cdot b^2} = \frac{8}{18}, which simplifies to b2=49b^2 = \frac{4}{9}.
3
Substitute the value of b2b^2 back into the first equation to solve for the initial mass aa.
a=40.5a = 40.5
Substituting b2b^2 gives a49=18a \cdot \frac{4}{9} = 18. Multiplying both sides by 94\frac{9}{4} yields a=1894=40.5a = 18 \cdot \frac{9}{4} = 40.5.

Anahtar Kavram

Solving systems of exponential equations to determine the initial value and decay factor.
Soru 2044Soru

At an agricultural research station, the nitrogen level of two soil plots, Plot A and Plot B, is monitored over several weeks. The nitrogen level of Plot A increases linearly at a constant rate, and the nitrogen level of Plot B increases exponentially at a constant percentage rate. At week t=0t = 0, Plot A contains 150 grams150\text{ grams} of nitrogen and Plot B contains 80 grams80\text{ grams} of nitrogen. At week t=2t = 2, both plots contain the same amount of nitrogen, which is 180 grams180\text{ grams}. At week t=4t = 4, Plot B contains N gramsN\text{ grams} of nitrogen and Plot A contains A gramsA\text{ grams} of nitrogen. What is the value of NAN - A?

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Cevap: 195

Cevap

195
The correct answer is 195195. At t=0t = 0, Plot A contains 150 grams150\text{ grams} and Plot B contains 80 grams80\text{ grams}. Since Plot A increases linearly and reaches 180 grams180\text{ grams} at t=2t = 2, its weekly rate of change is 1801502=15 grams per week\frac{180 - 150}{2} = 15\text{ grams per week}. Thus, at week t=4t = 4, Plot A contains 150+15(4)=210 grams150 + 15(4) = 210\text{ grams}. Since Plot B increases exponentially and reaches 180 grams180\text{ grams} at t=2t = 2, its weekly growth factor bb satisfies 80b2=18080b^2 = 180, which gives b2=2.25b^2 = 2.25 and b=1.5b = 1.5. Thus, at week t=4t = 4, Plot B contains 80(1.5)4=405 grams80(1.5)^4 = 405\text{ grams}. The difference NAN - A is 405210=195405 - 210 = 195.

Adım Adım Çözüm

1
Find the nitrogen level of Plot A at week t=4t = 4 using a linear model.
A=210A = 210
Plot A grows linearly from an initial 150 grams150\text{ grams} at t=0t = 0 to 180 grams180\text{ grams} at t=2t = 2. The rate of increase is 1801502=15 grams per week\frac{180 - 150}{2} = 15\text{ grams per week}. Thus, at t=4t = 4, the nitrogen level is 150+15(4)=210 grams150 + 15(4) = 210\text{ grams}.
2
Find the nitrogen level of Plot B at week t=4t = 4 using an exponential model.
N=405N = 405
Plot B grows exponentially from an initial 80 grams80\text{ grams} at t=0t = 0 to 180 grams180\text{ grams} at t=2t = 2. The weekly growth factor bb satisfies 80b2=18080b^2 = 180, so b2=2.25b^2 = 2.25 and b=1.5b = 1.5. Thus, at t=4t = 4, the nitrogen level is 80(1.5)4=80(5.0625)=405 grams80(1.5)^4 = 80(5.0625) = 405\text{ grams}.
3
Calculate the difference between the two nitrogen levels at week t=4t = 4.
195195
Subtracting AA from NN yields NA=405210=195N - A = 405 - 210 = 195.

Anahtar Kavram

Modeling linear growth (constant rate of change) and exponential growth (constant percentage rate of change or growth factor) over time.
Soru 2045Soru

A trapezoid has parallel bases of length 66 centimeters and 1010 centimeters, and a height of 55 centimeters. What is the area, in square centimeters, of the trapezoid?

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Cevap: 40

Cevap

The area of the trapezoid is 4040 square centimeters.
The area of a trapezoid is calculated using the formula A=a+b2hA = \frac{a + b}{2} h, where aa and bb are the lengths of the parallel bases and hh is the height. Substituting the given values a=6a = 6, b=10b = 10, and h=5h = 5 into the formula yields A=6+102×5=8×5=40A = \frac{6 + 10}{2} \times 5 = 8 \times 5 = 40.

Adım Adım Çözüm

1
Recall the area formula for a trapezoid.
A=a+b2hA = \frac{a + b}{2}h
The area of a trapezoid is the average of its parallel bases multiplied by its height.
2
Substitute the base values of 66 and 1010, and the height value of 55 into the formula.
A=6+102×5A = \frac{6 + 10}{2} \times 5
This sets up the calculation with the given measurements.
3
Simplify the expression to find the final area.
A=40A = 40
Adding the bases gives 1616, dividing by 22 gives 88, and multiplying by the height of 55 results in 4040.

Anahtar Kavram

Area of a Trapezoid
Tahmini Süre:45s
Soru 2046Soru

The table below shows the distribution of a group of 180180 commuters surveyed about their primary mode of transportation and their daily commuting distance.

Commuting DistancePublic TransitPersonal Vehicle
Under 10 miles4535
10 miles or more6040

Based on the table, if a commuter who primarily uses a personal vehicle is selected at random, what is the probability that this commuter has a daily commuting distance of under 10 miles?

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Cevap: 715\frac{7}{15}

Cevap

The probability that the selected commuter has a daily commuting distance of under 10 miles, given that they primarily use a personal vehicle, is 715\frac{7}{15}.
To find the probability that a commuter has a daily commuting distance of under 10 miles given that they primarily use a personal vehicle, we limit our sample space to only the commuters who use a personal vehicle. The total number of commuters who primarily use a personal vehicle is 35+40=7535 + 40 = 75. Within this group, the number of commuters with a daily commuting distance of under 10 miles is 35. Therefore, the probability is the fraction 3575\frac{35}{75}, which simplifies to 715\frac{7}{15}.

Adım Adım Çözüm

1
Identify the total number of commuters who satisfy the condition of primarily using a personal vehicle.
The total number of commuters who primarily use a personal vehicle is 35+40=7535 + 40 = 75.
This sum represents the total number of possible outcomes (the denominator) because the selection is restricted to this group.
2
Identify the number of commuters within that subset who have a daily commuting distance of under 10 miles.
The number of personal vehicle commuters with a daily commuting distance of under 10 miles is 35.
This represents the number of favorable outcomes (the numerator).
3
Divide the number of favorable outcomes by the total number of possible outcomes and simplify the resulting fraction.
The probability is 3575=715\frac{35}{75} = \frac{7}{15}.
Dividing the numerator and denominator by their greatest common divisor, 5, gives the simplified probability.

Anahtar Kavram

Calculating conditional probability from a two-way table by identifying the correct subset of the population to use as the denominator.
Tahmini Süre:1m 30s
Soru 2047Soru

If 5(2x9)+318-5(2x - 9) + 3 \geq 18, what is the maximum possible value of xx?

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Cevap: 3

Cevap

The correct answer is 3.
Distributing the 5-5 gives 10x+45+318-10x + 45 + 3 \geq 18. Combining constants yields 10x+4818-10x + 48 \geq 18. Subtracting 48 from both sides gives 10x30-10x \geq -30. Finally, dividing both sides by 10-10 and reversing the inequality sign gives x3x \leq 3. The maximum possible value is therefore 3.

Adım Adım Çözüm

1
Distribute 5-5 to the terms inside the parentheses.
10x+45+318-10x + 45 + 3 \geq 18
Simplify the expression by expanding the parentheses.
2
Combine the constant terms 4545 and 33 on the left side.
10x+4818-10x + 48 \geq 18
Group like terms together.
3
Subtract 4848 from both sides of the inequality.
10x30-10x \geq -30
Isolate the variable term.
4
Divide both sides by 10-10 and reverse the inequality symbol.
x3x \leq 3
Dividing by a negative number reverses the direction of the inequality.

Anahtar Kavram

Solving multi-step linear inequalities in one variable, applying the distributive property, and reversing the inequality sign when multiplying or dividing by a negative number.
Soru 2048Soru

A commercial cargo ship is unloading shipping containers at a port. The total mass of the ship and its remaining cargo, MM, in kilotonnes (kt), is a linear function of the number of hours, hh, since the unloading process began. After 33 hours of unloading, the total mass of the ship and its cargo is 116116 kt. After 88 hours of unloading, the total mass is 9898 kt. According to this model, what is the mass, in kilotonnes, of the cargo that is unloaded each hour?

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Cevap: 3.6

Cevap

The mass of the cargo unloaded each hour is 3.63.6 kilotonnes (or the equivalent fraction 185\frac{18}{5}).
The correct answer is 3.63.6. Since the relationship between the total mass of the ship and cargo, MM, and the elapsed time, hh, is linear, the rate at which cargo is unloaded corresponds to the magnitude of the slope of the linear function. Using the two data points (3,116)(3, 116) and (8,98)(8, 98), the slope mm can be calculated as 9811683=185=3.6\frac{98 - 116}{8 - 3} = \frac{-18}{5} = -3.6. The negative sign indicates that the mass is decreasing, meaning that 3.63.6 kilotonnes of cargo are unloaded each hour.

Adım Adım Çözüm

1
Set up the linear relationship model.
M=mh+bM = mh + b
Since the relationship between total mass MM and time hh is linear, it can be modeled by a linear equation where mm is the slope (unloading rate) and bb is the y-intercept (initial mass).
2
Determine the two data points from the given information.
(3,116)(3, 116) and (8,98)(8, 98)
After 33 hours of unloading, the mass is 116116 kt, and after 88 hours, the mass is 9898 kt.
3
Calculate the slope (rate of change) of the linear relationship.
m=3.6m = -3.6
The slope is calculated as m=9811683=185=3.6m = \frac{98 - 116}{8 - 3} = \frac{-18}{5} = -3.6.
4
Interpret the slope's value in context to find the amount of cargo unloaded per hour.
3.63.6
The slope is 3.6-3.6 kilotonnes per hour, which means the total mass decreases by 3.63.6 kilotonnes each hour. Therefore, the mass of the cargo unloaded each hour is 3.63.6 kilotonnes.

Anahtar Kavram

Interpreting the slope of a linear relationship in context
Tahmini Süre:1m 30s
Soru 2049Soru

In cognitive psychology, change blindness refers to the tendency of observers to fail to notice significant changes in a visual scene. Researchers study this phenomenon by inserting a brief disruption between two versions of an ______ many participants fail to detect the alteration because the brain does not store every visual detail.

Which choice completes the text so that it conforms to the conventions of Standard English?

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Cevap: image;

Cevap

image;
The semicolon correctly links the two independent clauses without a coordinating conjunction, conforming to the conventions of Standard English.

Adım Adım Çözüm

1
Identify the clause boundaries in the sentence.
The sentence contains two independent clauses: 'Researchers study this phenomenon by inserting a brief disruption between two versions of an image' and 'many participants fail to detect the alteration because the brain does not store every visual detail.'
Both clauses contain a subject and a verb and can express a complete thought independently.
2
Determine the appropriate punctuation or conjunction to link these clauses.
Two independent clauses must be joined by a period, a semicolon, a colon (if the second explains the first), or a comma followed by a coordinating conjunction (FANBOYS).
Joining them with only a comma creates a comma splice, and joining them with no punctuation creates a run-on sentence.
3
Evaluate the choices to find the grammatically and logically correct option.
The option containing a semicolon correctly links the two clauses. The option with a comma creates an ungrammatical comma splice. The option with no punctuation creates an ungrammatical run-on. The option with the comma and coordinator 'but' is grammatically possible but logically incorrect since there is no contrast between the clauses.
The semicolon is the only choice that maintains grammatical correctness and logical flow.

Anahtar Kavram

Semicolons are used to connect two closely related independent clauses that are not joined by a coordinating conjunction.
Soru 2050Soru

The quadratic equation x28x9=0x^2 - 8x - 9 = 0 can be written in the equivalent form (xa)2b=0(x - a)^2 - b = 0, where aa and bb are positive constants. What is the value of a+ba + b?

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Cevap: 29

Cevap

The value of a+ba + b is 29.
Completing the square on the quadratic equation x28x9=0x^2 - 8x - 9 = 0 yields (x4)225=0(x - 4)^2 - 25 = 0. Comparing this to the form (xa)2b=0(x - a)^2 - b = 0 shows that a=4a = 4 and b=25b = 25. The sum of these values is 4+25=294 + 25 = 29.

Adım Adım Çözüm

1
Identify the coefficient of the linear term and find half of its value.
The coefficient of the linear term 8x-8x is 8-8. Half of 8-8 is 4-4.
This is the first step in completing the square.
2
Square the value obtained in the first step and add/subtract it in the equation to form a perfect square trinomial.
(4)2=16(-4)^2 = 16. The equation becomes (x28x+16)169=0(x^2 - 8x + 16) - 16 - 9 = 0.
Adding and subtracting 1616 maintains the equality while allowing us to group the first three terms as a perfect square.
3
Rewrite the perfect square trinomial and combine the remaining constant terms.
(x4)225=0(x - 4)^2 - 25 = 0.
This simplifies the equation into the desired equivalent form (xa)2b=0(x - a)^2 - b = 0.
4
Compare the equation to the target form (xa)2b=0(x - a)^2 - b = 0 to identify the constants aa and bb, and calculate a+ba + b.
a=4a = 4 and b=25b = 25. Therefore, a+b=4+25=29a + b = 4 + 25 = 29.
This answers the question by finding the sum of the positive constants aa and bb.

Anahtar Kavram

Completing the square to rewrite a quadratic equation
Soru 2051Soru

In right triangle ABCABC, the measure of angle BB is 9090^\circ. If sin(A)=513\sin(A) = \frac{5}{13}, what is the value of cos(C)\cos(C)?

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Cevap: 513\frac{5}{13}

Cevap

513\frac{5}{13}
The correct answer is 513\frac{5}{13}. In any right triangle ABCABC where the right angle is at BB, the two acute angles AA and CC are complementary, meaning A+C=90A + C = 90^\circ. The co-function identity states that the sine of an acute angle is equal to the cosine of its complement, or sin(A)=cos(90A)=cos(C)\sin(A) = \cos(90^\circ - A) = \cos(C). Given that sin(A)=513\sin(A) = \frac{5}{13}, the value of cos(C)\cos(C) must also be 513\frac{5}{13}.

Adım Adım Çözüm

1
Identify the relationship between the acute angles in a right triangle.
Since the measure of angle BB is 9090^\circ, the sum of the measures of angles AA and CC must be 9090^\circ. Thus, angles AA and CC are complementary.
The sum of angles in any triangle is 180180^\circ.
2
Apply the co-function identity for complementary angles.
For any two complementary angles AA and CC, the identity cos(C)=sin(A)\cos(C) = \sin(A) holds true.
The sine of an angle is the ratio of the opposite side to the hypotenuse, which is the same as the ratio of the adjacent side of its complement to the hypotenuse (cosine of the complement).
3
Substitute the given value to find cos(C)\cos(C).
Since sin(A)=513\sin(A) = \frac{5}{13}, it follows that cos(C)=513\cos(C) = \frac{5}{13}.
Direct substitution into the identity cos(C)=sin(A)\cos(C) = \sin(A).

Anahtar Kavram

Co-function identities for complementary angles in a right triangle
Soru 2052Soru

For the quadratic function ff, the table shows some values of xx and their corresponding values of f(x)f(x).

xxf(x)f(x)
111515
3333
551515

What is the value of f(0)f(0)?

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Cevap: 30

Cevap

30
Since the function values at x=1x = 1 and x=5x = 5 are both 1515, the axis of symmetry of the quadratic function must be located at the midpoint of these values, which is x=3x = 3. The vertex of the function must therefore have an xx-coordinate of 33. From the table, f(3)=3f(3) = 3, which means the vertex is (3,3)(3, 3). The vertex form of the quadratic function is f(x)=a(x3)2+3f(x) = a(x - 3)^2 + 3. To find the value of aa, substitute the point (1,15)(1, 15) into the equation: 15=a(13)2+315 = a(1 - 3)^2 + 3, which simplifies to 15=4a+315 = 4a + 3, giving a=3a = 3. The equation of the function is f(x)=3(x3)2+3f(x) = 3(x - 3)^2 + 3. Substituting x=0x = 0 yields f(0)=3(03)2+3=3(9)+3=30f(0) = 3(0 - 3)^2 + 3 = 3(9) + 3 = 30.

Adım Adım Çözüm

1
Find the axis of symmetry.
The axis of symmetry is x=3x = 3.
Since f(1)=15f(1) = 15 and f(5)=15f(5) = 15, the function values are equal at these points. Because a quadratic function is symmetric, the axis of symmetry is the midpoint of these two xx-values: 1+52=3\frac{1 + 5}{2} = 3.
2
Identify the vertex.
The vertex is (3,3)(3, 3).
The vertex of a quadratic function lies on its axis of symmetry. Since the axis of symmetry is x=3x = 3, the xx-coordinate of the vertex is 33. From the table, f(3)=3f(3) = 3, so the vertex is (3,3)(3, 3).
3
Write the function in vertex form and solve for the leading coefficient.
f(x)=3(x3)2+3f(x) = 3(x - 3)^2 + 3
The vertex form of a quadratic function is f(x)=a(xh)2+kf(x) = a(x - h)^2 + k, where (h,k)(h, k) is the vertex. Substituting (3,3)(3, 3), we get f(x)=a(x3)2+3f(x) = a(x - 3)^2 + 3. Using the point (1,15)(1, 15) from the table, we substitute x=1x = 1 and f(x)=15f(x) = 15: 15=a(13)2+315=4a+312=4aa=315 = a(1 - 3)^2 + 3 \Rightarrow 15 = 4a + 3 \Rightarrow 12 = 4a \Rightarrow a = 3.
4
Evaluate the function at x=0x = 0.
f(0)=30f(0) = 30
Substitute x=0x = 0 into the function: f(0)=3(03)2+3=3(9)+3=27+3=30f(0) = 3(0 - 3)^2 + 3 = 3(9) + 3 = 27 + 3 = 30.

Anahtar Kavram

Quadratic Functions and Graphs
Soru 2053Soru

Read the passage about the ecological effects of gray wolves. Which word or phrase logically completes the text by establishing a cause-and-effect connection?

Aşağıdaki boşlukları doldurun

In 1995, the reintroduction of gray wolves to Yellowstone National Park initiated a trophic cascade that altered the local ecosystem. By preying on elk, the wolves reduced elk populations and changed their grazing habits, allowing willow and aspen trees along riverbanks to regenerate. erosion decreased significantly, stabilizing the river channels and creating new habitats for beaver and fish species.
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Cevap

Consequently (or another cause-and-effect transition such as 'as a result', 'therefore', or 'thus')
The passage describes a sequence where the recovery of vegetation (willow and aspen trees) leads directly to the stabilization of soil and a decrease in erosion. Because the reduction in erosion is a direct consequence of the regenerated trees, a cause-and-effect transition like 'consequently', 'therefore', or 'as a result' is logically required to connect the sentences.

Adım Adım Çözüm

1
Analyze the relationship between the ideas in the passage.
The sentence before the blank describes how the reintroduction of wolves allowed riverbank vegetation (willow and aspen trees) to regenerate. The sentence containing the blank describes a decrease in soil erosion along the river channels.
Identifying the relationship between these two points is necessary to choose the correct transition.
2
Determine the logical connection.
The regeneration of riverbank vegetation directly caused the decrease in soil erosion (because tree roots stabilize soil). This represents a clear cause-and-effect relationship.
Establishing that the second point is a direct result of the first point requires a cause-and-effect transition.

Anahtar Kavram

Transitions: Cause and Effect
Soru 2054Soru

A dataset consists of 1111 positive integers. The mean of the dataset is 1414, and the median is 1212. The range of the dataset is 2020. If the maximum possible value of the largest integer in the dataset is LL, what is the value of LL?

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Cevap: 32

Cevap

The maximum possible value of the largest integer in the dataset is 3232.
The correct answer is 3232. Let the 11 integers in nondecreasing order be x1x2x11x_1 \le x_2 \le \dots \le x_{11}. Since the mean of the 11 integers is 1414, their sum is 11×14=15411 \times 14 = 154. Since the median is 1212, the 6th integer is x6=12x_6 = 12. The range is 2020, so x11x1=20x_{11} - x_1 = 20, which gives x1=x1120x_1 = x_{11} - 20. To maximize the largest integer x11x_{11}, we need to observe that x1x6=12x_1 \le x_6 = 12. Substituting x1=x1120x_1 = x_{11} - 20 into this inequality yields x112012x_{11} - 20 \le 12, which simplifies to x1132x_{11} \le 32. We can verify that x11=32x_{11} = 32 is achievable with the dataset: 12,12,12,12,12,12,12,12,12,14,3212, 12, 12, 12, 12, 12, 12, 12, 12, 14, 32. Therefore, the maximum possible value of the largest integer is 3232.

Adım Adım Çözüm

1
Calculate the sum of the 11 integers in the dataset.
The sum of the 11 integers is 154154.
Since the mean of 11 values is 14, their sum must be 11×14=15411 \times 14 = 154.
2
Identify the median and establish the order constraint.
The 6th value in the ordered list of 11 integers is 1212.
The median of an odd number of sorted values is the middle value, which is the 6th value (x6=12x_6 = 12).
3
Relate the minimum and maximum values using the range.
The minimum value x1x_1 is related to the maximum value x11x_{11} by x1=x1120x_1 = x_{11} - 20.
The range of the dataset is 20, which is the difference between the maximum and minimum values.
4
Find the maximum possible value of the largest integer.
The maximum value is 3232.
Since the dataset is sorted, the minimum value x1x_1 cannot exceed the median x6=12x_6 = 12. Therefore, x112    x112012    x1132x_1 \le 12 \implies x_{11} - 20 \le 12 \implies x_{11} \le 32.

Anahtar Kavram

Using measures of center (mean, median) and spread (range) to determine bounds on data values.
Soru 2055Soru

A right circular cylindrical container with a base radius of RR inches is partially filled with water. A solid metal sphere with a radius of rr inches is placed into the container and becomes completely submerged, causing the water level to rise by 1.51.5 inches without any water overflowing. The sphere is then removed, and a solid right circular cone with a base radius of rr inches and a height of 1212 inches is placed vertex-down into the container. When the cone is completely submerged, the water level is 11 inch higher than the container's original water level. What is the value of RR, in inches?

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Cevap: 9

Cevap

The radius of the cylinder, RR, is 99 inches.
The volume of a submerged solid is equal to the volume of the cylinder of water it displaces. By setting up equations for the sphere and the cone, we get 43r3=1.5R2\frac{4}{3}r^3 = 1.5 R^2 and 4r2=R24r^2 = R^2. Substituting the second equation into the first yields r=4.5r = 4.5, which then gives R=2r=9R = 2r = 9.

Adım Adım Çözüm

1
Equate the volume of the sphere to the volume of water it displaces in the cylinder.
43πr3=1.5πR2    43r3=1.5R2\frac{4}{3}\pi r^3 = 1.5\pi R^2 \implies \frac{4}{3}r^3 = 1.5 R^2
The volume of a submerged solid equals the volume of the fluid it displaces. The displaced fluid takes the shape of a cylinder of radius RR and height equal to the water level rise (1.51.5 inches).
2
Equate the volume of the cone to the volume of water it displaces in the cylinder.
13πr2(12)=1.0πR2    4r2=R2\frac{1}{3}\pi r^2 (12) = 1.0\pi R^2 \implies 4r^2 = R^2
Similarly, the volume of the cone is equal to the volume of a cylinder of radius RR and height equal to the water level rise (11 inch).
3
Solve the system of equations by substituting R2R^2 into the sphere's displacement equation.
43r3=1.5(4r2)    43r3=6r2    r=4.5\frac{4}{3}r^3 = 1.5(4r^2) \implies \frac{4}{3}r^3 = 6r^2 \implies r = 4.5
By replacing R2R^2 with 4r24r^2, we reduce the system of equations to a single equation containing only rr. Since r0r \neq 0, we can divide by r2r^2 to solve for rr directly.
4
Calculate the value of RR from the relationship between RR and rr.
R=2r=2(4.5)=9R = 2r = 2(4.5) = 9
Since R2=4r2R^2 = 4r^2 and radii must be positive quantities, R=2rR = 2r.

Anahtar Kavram

Using water displacement to relate the volumes of three-dimensional geometric solids (cylinders, spheres, cones) and solving non-linear systems of equations.
Soru 2056Soru

A container in the shape of a right circular cylinder with a base radius of 44 inches and a height of 99 inches is completely filled with water. All of the water from this cylinder is poured into an empty container in the shape of a rectangular prism. The rectangular prism container has a square base of side length 66 inches and a height of 1515 inches. If the height of the water in the rectangular prism container is kπk\pi inches, what is the value of kk?

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Cevap: 4

Cevap

The value of kk is 44.
To find the height of the water in the rectangular prism, we first calculate the volume of the water using the cylinder's volume formula, V=πr2hV = \pi r^2 h. With a radius of 44 inches and a height of 99 inches, the volume is π(4)2(9)=144π\pi (4)^2 (9) = 144\pi cubic inches. When this water is poured into the rectangular prism, the volume of the water can also be represented as the area of the base times the height of the water: V=Base Area×hw=62×hw=36hwV = \text{Base Area} \times h_w = 6^2 \times h_w = 36 h_w. Equating the two volumes gives 36hw=144π36 h_w = 144\pi, which simplifies to hw=4πh_w = 4\pi inches. Since the height of the water in the prism is kπk\pi inches, the value of kk is 44.

Adım Adım Çözüm

1
Calculate the volume of the water in the filled cylinder using the formula V=πr2hV = \pi r^2 h.
The volume of the water is 144π144\pi cubic inches.
Since the cylinder is completely filled, the volume of the water is equal to the volume of the cylinder with base radius 44 inches and height 99 inches.
2
Calculate the area of the square base of the rectangular prism container.
The base area is 3636 square inches.
The base of the prism is a square with side length 66 inches, so its area is 6×6=366 \times 6 = 36 square inches.
3
Set the volume of the water in the rectangular prism equal to the volume of the water from the cylinder, and solve for the water height hwh_w.
36×hw=144π    hw=4π36 \times h_w = 144\pi \implies h_w = 4\pi inches.
Pouring the water into the prism container does not change its volume, which remains 144π144\pi cubic inches. The volume of a prism is the base area times its height.
4
Compare the height of the water 4π4\pi to the expression kπk\pi to find kk.
k=4k = 4.
Since the height of the water is represented as kπk\pi inches and we calculated it to be 4π4\pi inches, kk must equal 44.

Anahtar Kavram

Equating the volumes of a right circular cylinder and a rectangular prism to solve for an unknown dimension.
Soru 2057Soru

A solid metal right circular cylinder has a base radius of 12 centimeters12\text{ centimeters} and a height of 3 centimeters3\text{ centimeters}. A cone with the same base and height as the cylinder is carved out and removed. The remaining metal is melted and recast into a solid sphere. What is the radius, in centimeters, of the sphere?

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Cevap: 6

Cevap

The radius of the sphere is 6 centimeters.
The volume of a cylinder is V=πr2h=π(12)2(3)=432πV = \pi r^2 h = \pi (12)^2 (3) = 432\pi. The volume of the carved-out cone is V=13πr2h=13π(12)2(3)=144πV = \frac{1}{3}\pi r^2 h = \frac{1}{3}\pi (12)^2 (3) = 144\pi. Subtracting the cone's volume from the cylinder's volume yields the remaining metal volume: 432π144π=288π432\pi - 144\pi = 288\pi. The volume of the recast sphere is 43πR3=288π\frac{4}{3}\pi R^3 = 288\pi. Dividing by π\pi and multiplying by 34\frac{3}{4} gives R3=216R^3 = 216. Taking the cube root of both sides gives the radius R=6R = 6.

Adım Adım Çözüm

1
Calculate the volume of the original cylinder.
432π cubic centimeters432\pi\text{ cubic centimeters}
This determines the starting volume of the solid metal block before any material is removed.
2
Calculate the volume of the cone that is carved out.
144π cubic centimeters144\pi\text{ cubic centimeters}
This determines how much metal is discarded from the cylinder.
3
Subtract the cone's volume from the cylinder's volume.
288π cubic centimeters288\pi\text{ cubic centimeters}
This gives the volume of the remaining metal that will be melted and recast.
4
Equate the remaining volume to the volume formula of a sphere and solve for the radius.
6 centimeters6\text{ centimeters}
This yields the radius of the newly formed sphere.

Anahtar Kavram

Volume of composite solids and conservation of volume during recasting
Soru 2058Soru

A municipal research group conducted a survey of a random sample of n1n_1 registered voters in a city to estimate the proportion of voters who support a proposed school bond. In this survey, the proportion of voters who supported the bond was 0.520.52, with an associated margin of error of 0.060.06 at a 95%95\% confidence level. The group plans to conduct a follow-up survey of a random sample of n2n_2 registered voters from the same population. Assuming the sample proportion remains approximately the same, and the group wants the margin of error for the follow-up survey to be 0.020.02 at the same 95%95\% confidence level, what is the value of the ratio n2n1\frac{n_2}{n_1}?

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Cevap: 9

Cevap

9
The margin of error for a sample proportion is inversely proportional to the square root of the sample size. Since the target margin of error is one-third of the initial margin of error (from 0.060.06 to 0.020.02), the sample size must be increased by a factor of 32=93^2 = 9. Thus, the ratio of the new sample size to the original sample size is 99.

Adım Adım Çözüm

1
State the formula for the margin of error of a sample proportion.
E=zp^(1p^)nE = z^* \sqrt{\frac{\hat{p}(1-\hat{p})}{n}}
This formula defines the mathematical relationship between the margin of error, the confidence level (via the critical value zz^*), the sample proportion p^\hat{p}, and the sample size nn.
2
Determine the relationship between margin of error and sample size when other variables are constant.
E1nE \propto \frac{1}{\sqrt{n}}
Since the confidence level remains at 95%95\% (constant zz^*) and the sample proportion remains approximately the same (constant p^\hat{p}), the margin of error is inversely proportional to the square root of the sample size.
3
Set up the ratio equation for the two surveys.
E1E2=n2n1\frac{E_1}{E_2} = \sqrt{\frac{n_2}{n_1}}
Dividing the expression for the first margin of error by the expression for the second margin of error simplifies to the square root of the ratio of the second sample size to the first sample size.
4
Substitute the given margins of error and solve for the ratio.
n2n1=9\frac{n_2}{n_1} = 9
Substitute E1=0.06E_1 = 0.06 and E2=0.02E_2 = 0.02 to get 0.060.02=3=n2n1\frac{0.06}{0.02} = 3 = \sqrt{\frac{n_2}{n_1}}. Squaring both sides yields the ratio of the sample sizes, which is 99.

Anahtar Kavram

The relationship between sample size and margin of error in statistical studies.
Soru 2059Soru

While planning a presentation, a student takes the following notes:
* Kepler-186f is an exoplanet that orbits a red dwarf star known as Kepler-186.
* It belongs to a category of planets that are similar in size to Earth and orbit within their host star's habitable zone.
* The habitable zone is defined as the orbital region around a star where liquid water could potentially exist on a planet's surface.
* Orbiting within this zone does not guarantee habitability, as a planet's surface temperatures depend heavily on its atmospheric composition.
* For example, Kepler-186f receives only one-third of the stellar energy that Earth does, meaning it requires a thick greenhouse atmosphere to prevent freezing.

The student wants to present a generalization about the category of Earth-sized planets in habitable zones. Which choice most effectively uses information from the given notes to accomplish this goal?

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Cevap: While Earth-sized planets in habitable zones have the potential to support liquid water, their actual habitability is determined by whether their atmospheres can maintain temperatures above freezing.

Cevap

The option stating that while Earth-sized planets in habitable zones have the potential to support liquid water, their actual habitability is determined by whether their atmospheres can maintain temperatures above freezing.
The correct option successfully presents a generalization about the category of Earth-sized planets in habitable zones. It synthesizes the information from the notes regarding their potential for liquid water and the critical role of atmospheric composition in determining their actual surface temperatures, without limiting the statement to the specific example of Kepler-186f.

Adım Adım Çözüm

1
Analyze the prompt to identify the student's rhetorical goal.
The goal is to present a generalization about the category of Earth-sized planets in habitable zones.
This determines which information must be prioritized and how the final statement should be framed.
2
Evaluate the notes to determine the key characteristics of the category.
The category consists of Earth-sized planets in habitable zones (where water could exist), but habitability is not guaranteed and depends on atmospheric composition.
This establishes the factual basis for the correct generalization.
3
Assess the options to find the one that generalizes about the category without focusing solely on the example of Kepler-186f.
The statement describing the potential for water vs. the role of atmosphere in these planets is a valid generalization, whereas other choices focus too narrowly on Kepler-186f or misrepresent the notes.
Selecting the option that matches the category-level generalization ensures the rhetorical goal is met.

Anahtar Kavram

Rhetorical Synthesis: Summarization and Generalization
Soru 2060Soru

A financial technology platform offers two merchant rewards programs, Program PP and Program EE, based on a merchant's monthly transaction volume. The table below shows the monthly reward for both programs at a transaction volume of $50,000\$50,000.

ProgramGrowth ModelReward at $50,000\$50,000 Volume
Program PPLinear$800\$800
Program EEExponential$800\$800

For every increase of $10,000\$10,000 in monthly transaction volume:
- Under Program PP, the monthly reward increases by $150\$150.
- Under Program EE, the monthly reward increases by 5%5\%.

If a merchant's monthly transaction volume increases from $50,000\$50,000 to $90,000\$90,000, what is the closest dollar amount to the difference between the monthly rewards the merchant would receive under the two programs?

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Cevap: $428

Cevap

$428
The correct answer of $428\$428 represents the difference between the rewards under the two models at a monthly transaction volume of $90,000\$90,000. The number of $10,000\$10,000 increments from $50,000\$50,000 to $90,000\$90,000 is 44. The linear reward under Program P increases by $150\$150 per increment, resulting in a reward of 800+4(150)=1400800 + 4(150) = 1400. The exponential reward under Program E increases by 5%5\% per increment, resulting in a reward of 800×(1.05)4972.41800 \times (1.05)^4 \approx 972.41. The difference is 1400972.41=427.591400 - 972.41 = 427.59, which is closest to $428\$428.

Adım Adım Çözüm

1
Determine the number of $10,000\$10,000 increments from the initial transaction volume to the target volume.
44 increments
The transaction volume increases from $50,000\$50,000 to $90,000\$90,000, a change of $40,000\$40,000. Since the growth rates are defined per $10,000\$10,000 increase, the number of increments is 40,00010,000=4\frac{40,000}{10,000} = 4.
2
Calculate the monthly reward under the linear model (Program P) after 44 increments.
14001400 dollars
Program P adds a constant $150\$150 per increment. The reward after 44 increments is 800+4(150)=800+600=1400800 + 4(150) = 800 + 600 = 1400.
3
Calculate the monthly reward under the exponential model (Program E) after 44 increments.
972.41972.41 dollars
Program E increases by a constant percent (5%5\%) per increment, which corresponds to a growth factor of 1.051.05. The reward after 44 increments is 800×(1.05)4800×1.2155=972.41800 \times (1.05)^4 \approx 800 \times 1.2155 = 972.41.
4
Find the difference between the two monthly rewards.
427.59427.59 dollars, which rounds to 428428 dollars
Subtract the reward under Program E from the reward under Program P: 1400972.41=427.591400 - 972.41 = 427.59.

Anahtar Kavram

Distinguishing between linear and exponential growth models and evaluating them at specific values in a real-world context.
Tahmini Süre:2m 30s
ÖncekiSayfa 103 / 140Sonraki
Tüm alıştırma soruları — SAT | Examkin