Problem-Solving and Data Analysis

179 soru

Soru 41Soru

A technician at a chemistry lab prepares a solution by mixing 33 milliliters of acid with every 77 milliliters of distilled water. If the technician uses 3535 milliliters of distilled water to prepare the solution, how many milliliters of acid are needed?

Cevabı ve açıklamayı göster

Cevap: 15

Cevap

The correct answer is 15.
To maintain the ratio of 33 milliliters of acid for every 77 milliliters of distilled water, the proportion acidwater=37=x35\frac{\text{acid}}{\text{water}} = \frac{3}{7} = \frac{x}{35} is established. Multiplying both sides by 3535 gives x=35×37=15x = 35 \times \frac{3}{7} = 15 milliliters of acid.

Adım Adım Çözüm

1
Set up the proportion relating acid to distilled water.
37=x35\frac{3}{7} = \frac{x}{35}, where xx is the required amount of acid in milliliters.
The ratio of acid to distilled water must remain constant.
2
Solve the proportion for xx.
x=15x = 15
Multiply both sides of the equation by 35 to isolate xx.

Anahtar Kavram

Solving proportions to find an unknown quantity when the ratio is constant.

Alternatif Yöntem

Find the scale factor: 3535 divided by 77 is 55. Multiply the acid amount (33) by this scale factor of 55 to get 1515.
Tahmini Süre:45s
Soru 42Soru

An agricultural drone sprays liquid fertilizer at a rate of 1.51.5 fluid ounces per square yard. The drone travels at a constant speed of 4.54.5 miles per hour, spraying a continuous path that is exactly 66 feet wide. Which of the following is closest to the rate at which the drone sprays the fertilizer, in gallons per minute? (Given that 1 mile=5,280 feet1\text{ mile} = 5,280\text{ feet}, 1 yard=3 feet1\text{ yard} = 3\text{ feet}, and 1 gallon=128 fluid ounces1\text{ gallon} = 128\text{ fluid ounces})

Cevabı ve açıklamayı göster

Cevap: 3.09

Cevap

The rate of 3.093.09 gallons per minute is closest to the drone's fertilizer spraying rate.
The correct answer is 3.093.09 because converting the speed of 4.54.5 miles per hour gives 396396 feet per minute. Multiplying this by the width of 66 feet results in 2,3762,376 square feet per minute. Dividing this by 99 converts the rate to 264264 square yards per minute. Multiplying by the spray density of 1.51.5 fluid ounces per square yard gives 396396 fluid ounces per minute. Finally, dividing by 128128 fluid ounces per gallon yields approximately 3.093.09 gallons per minute.

Adım Adım Çözüm

1
Convert the speed of the drone from miles per hour to feet per minute.
4.5 miles/hour=396 feet/minute4.5\text{ miles/hour} = 396\text{ feet/minute}
To find the rate of area covered per minute, the speed must first be expressed in feet per minute. Multiply 4.54.5 by 5,2805,280 to convert to feet per hour, then divide by 6060 to convert to feet per minute: 4.5×5,28060=396\frac{4.5 \times 5,280}{60} = 396.
2
Calculate the area covered by the drone per minute in square feet.
396 feet/minute×6 feet=2,376 square feet/minute396\text{ feet/minute} \times 6\text{ feet} = 2,376\text{ square feet/minute}
Multiplying the travel speed in feet per minute by the path width of 66 feet gives the area covered per minute in square feet.
3
Convert the area rate from square feet per minute to square yards per minute.
2,376 square feet/minute÷9=264 square yards/minute2,376\text{ square feet/minute} \div 9 = 264\text{ square yards/minute}
Since 1 yard=3 feet1\text{ yard} = 3\text{ feet}, a square yard is 3×3=93 \times 3 = 9 square feet. Therefore, divide the area in square feet by 99 to convert to square yards.
4
Determine the fertilizer spray rate in fluid ounces per minute.
264 square yards/minute×1.5 fluid ounces/square yard=396 fluid ounces/minute264\text{ square yards/minute} \times 1.5\text{ fluid ounces/square yard} = 396\text{ fluid ounces/minute}
Multiplying the area covered per minute by the spray density yields the volume of fertilizer sprayed per minute.
5
Convert the spray rate from fluid ounces per minute to gallons per minute.
396 fluid ounces/minute÷1283.09 gallons/minute396\text{ fluid ounces/minute} \div 128 \approx 3.09\text{ gallons/minute}
Since 1 gallon=128 fluid ounces1\text{ gallon} = 128\text{ fluid ounces}, divide the fluid ounces per minute by 128128 to find the rate in gallons per minute.

Anahtar Kavram

Unit conversions involving compound rates and area scaling.
Tahmini Süre:3m 0s
Soru 43Soru

At a certain car dealership, the number of hybrid vehicles sold in 2024 was 40%40\% of the number of gasoline vehicles sold in 2024. In 2025, the number of hybrid vehicles sold increased by 35%35\% compared to 2024, and the number of gasoline vehicles sold decreased by 10%10\% compared to 2024. If the dealership only sold hybrid and gasoline vehicles in both years, what percent of the total vehicles sold in 2025 were hybrid vehicles?

Cevabı ve açıklamayı göster

Cevap: 37.5

Cevap

37.5
To find the percentage of hybrid vehicles sold in 2025, we first express the number of vehicles sold in 2024 in terms of a single variable. Let the number of gasoline vehicles sold in 2024 be gg. Since the hybrid sales were 40%40\% of the gasoline sales, the number of hybrid vehicles sold in 2024 is 0.40g0.40g. In 2025, hybrid sales increased by 35%35\%, resulting in 0.40g×1.35=0.54g0.40g \times 1.35 = 0.54g hybrid vehicles sold. Gasoline sales decreased by 10%10\%, resulting in g×0.90=0.90gg \times 0.90 = 0.90g gasoline vehicles sold. The total number of vehicles sold in 2025 is the sum of these two quantities: 0.54g+0.90g=1.44g0.54g + 0.90g = 1.44g. The percentage of hybrid vehicles sold in 2025 is the ratio of hybrid sales to total sales: 0.54g1.44g×100=37.5%\frac{0.54g}{1.44g} \times 100 = 37.5\%.

Adım Adım Çözüm

1
Define variables for the number of vehicles sold in 2024.
Let the number of gasoline vehicles sold in 2024 be gg. The number of hybrid vehicles sold in 2024 is 0.40g0.40g.
Establishing initial values in terms of a single variable allows for comparison after percentage changes are applied.
2
Determine the number of hybrid and gasoline vehicles sold in 2025 after their respective percentage changes.
Hybrid vehicles sold in 2025: 0.40g×(1+0.35)=0.54g0.40g \times (1 + 0.35) = 0.54g. Gasoline vehicles sold in 2025: g×(10.10)=0.90gg \times (1 - 0.10) = 0.90g.
Applying the percent increase of 35%35\% to the 2024 hybrid vehicles and the percent decrease of 10%10\% to the 2024 gasoline vehicles.
3
Calculate the total number of vehicles sold in 2025.
Total vehicles sold in 2025: 0.54g+0.90g=1.44g0.54g + 0.90g = 1.44g.
Summing the two types of vehicles sold in 2025 to find the new total.
4
Compute the percentage of hybrid vehicles out of the total vehicles sold in 2025.
0.54g1.44g×100=37.5%\frac{0.54g}{1.44g} \times 100 = 37.5\%.
Dividing the 2025 hybrid sales by the total 2025 sales and multiplying by 100 to convert to a percentage.

Anahtar Kavram

Calculating percent change and conditional percentages from initial relative ratios.
Soru 44Soru

During a science experiment, a liquid is cooled at a constant rate of 0.50.5 degrees Celsius per minute. What is the cooling rate of the liquid, in degrees Celsius per hour?

Cevabı ve açıklamayı göster

Cevap: 30

Cevap

The cooling rate of the liquid is 3030 degrees Celsius per hour.
To find the cooling rate in degrees Celsius per hour, we multiply the rate per minute by the conversion factor. There are 6060 minutes in 11 hour. Multiplying 0.50.5 degrees Celsius per minute by 6060 minutes per hour yields 3030 degrees Celsius per hour.

Adım Adım Çözüm

1
Identify the initial cooling rate per minute.
0.50.5 degrees Celsius per minute
This is the rate given in the problem statement.
2
Convert minutes to hours by multiplying the rate by 6060.
3030 degrees Celsius per hour
An hour contains 6060 minutes, so the total temperature decrease in one hour will be 6060 times the decrease in one minute.

Anahtar Kavram

Unit conversions involving rates
Soru 45Soru

A local veterinarian clinic recorded the primary diets of 120 animals (cats and dogs). The results are summarized in the table below.

AnimalDry foodWet foodTotal
Cats352560
Dogs451560
Total8040120

If one of these animals is selected at random, what is the probability that the animal is a dog, given that the animal's primary diet is dry food?

Cevabı ve açıklamayı göster

Cevap: 916\frac{9}{16}

Cevap

The correct answer is the option representing 916\frac{9}{16}.
The correct answer is 916\frac{9}{16}. To find the probability that the selected animal is a dog given that its primary diet is dry food, we restrict our focus to the animals that eat dry food. According to the table, there are 80 animals in total whose primary diet is dry food. Among these 80 animals, 45 are dogs. Therefore, the probability is 4580\frac{45}{80}, which simplifies to 916\frac{9}{16}.

Adım Adım Çözüm

1
Identify the given condition in the question.
The condition is that the selected animal's primary diet is dry food.
This restricts the sample space to only the animals in the 'Dry food' column.
2
Find the total number of animals that meet the given condition from the table.
The total number of animals whose primary diet is dry food is 80.
This value serves as the denominator for the conditional probability fraction.
3
Find the number of dogs within the conditional space identified in the previous step.
The number of dogs that eat dry food is 45.
This value serves as the numerator representing the favorable outcomes.
4
Calculate the conditional probability by dividing the favorable outcomes by the total outcomes in the restricted sample space.
4580=916\frac{45}{80} = \frac{9}{16}
Dividing the numerator by the denominator and simplifying by dividing both by 5 yields the final probability.

Anahtar Kavram

Conditional Probability from Two-Way Tables

Alternatif Yöntem

Instead of working directly with the counts in the table, you can write the conditional probability formula: P(DogDry)=P(DogDry)P(Dry)=45/12080/120=4580=916P(\text{Dog} \mid \text{Dry}) = \frac{P(\text{Dog} \cap \text{Dry})}{P(\text{Dry})} = \frac{45/120}{80/120} = \frac{45}{80} = \frac{9}{16}.
Tahmini Süre:50s
Soru 46Soru

A technology company has two regional offices, Office North and Office South. In 2024, the number of employees at Office North was 25%25\% greater than the number of employees at Office South. In 2025, the number of employees at Office North increased by 20%20\%, and the number of employees at Office South decreased by 10%10\%. If the total number of employees at both offices combined in 2025 was 432432, what was the total number of employees at both offices combined in 2024?

Cevabı ve açıklamayı göster

Cevap: 405

Cevap

405
Let SS represent the number of employees at Office South in 2024. Because Office North has 25%25\% more employees than Office South in 2024, the count at Office North is 1.25S1.25S. The combined total in 2024 is S+1.25S=2.25SS + 1.25S = 2.25S. In 2025, Office North's staff increases by 20%20\%, making it 1.20×1.25S=1.50S1.20 \times 1.25S = 1.50S. Office South's staff decreases by 10%10\%, making it 0.90S0.90S. The combined total in 2025 is 1.50S+0.90S=2.40S1.50S + 0.90S = 2.40S. Given that the total in 2025 is 432432, we solve the equation 2.40S=4322.40S = 432, which gives S=180S = 180. Substituting S=180S = 180 into the expression for the 2024 total yields 2.25×180=4052.25 \times 180 = 405.

Adım Adım Çözüm

1
Define variables for the number of employees in 2024. Let SS be the number of employees at Office South in 2024. Since Office North had 25%25\% more employees, represent Office North as 1.25S1.25S. Express the total number of employees in 2024 as S+1.25S=2.25SS + 1.25S = 2.25S.
Total employees in 2024 is represented by 2.25S2.25S.
To establish a baseline relationship between the employee counts at the two offices.
2
Express the number of employees in 2025 in terms of SS by applying the percentage changes. Office North's employees increased by 20%20\%, which is 1.20×1.25S=1.50S1.20 \times 1.25S = 1.50S. Office South's employees decreased by 10%10\%, which is 0.90×S=0.90S0.90 \times S = 0.90S. Find the total in 2025 by adding these values: 1.50S+0.90S=2.40S1.50S + 0.90S = 2.40S.
Total employees in 2025 is represented by 2.40S2.40S.
To determine the algebraic expression representing the combined count after the percent changes.
3
Set the algebraic expression for the 2025 total equal to the given value of 432432 and solve for SS.
2.40S=432    S=1802.40S = 432 \implies S = 180
To find the baseline number of employees at Office South in 2024.
4
Substitute S=180S = 180 back into the expression for the 2024 total (2.25S2.25S) to calculate the final answer.
2.25×180=4052.25 \times 180 = 405
To calculate the combined total number of employees in 2024.

Anahtar Kavram

Percents and Percent Change
Tahmini Süre:1m 30s
Soru 47Soru

To make a specific shade of green paint, a painter mixes yellow paint and blue paint in a ratio of 33 to 55. If the painter wants to make a total of 4040 gallons of this green paint, how many gallons of yellow paint are needed?

Cevabı ve açıklamayı göster

Cevap: 1515

Cevap

The correct amount of yellow paint needed is 1515 gallons.
The correct answer is 1515 gallons. Since the ratio of yellow to blue paint is 3:53:5, the total mixture consists of 3+5=83 + 5 = 8 equal parts. Yellow paint represents 33 of these 88 parts, or 38\frac{3}{8} of the total mixture. To find the amount of yellow paint needed for 4040 gallons of green paint, multiply the fraction by the total volume: 38×40=15\frac{3}{8} \times 40 = 15 gallons.

Adım Adım Çözüm

1
Determine the fraction of the total mixture that is yellow paint.
The ratio of yellow to blue paint is 3:53:5, which gives a total of 3+5=83 + 5 = 8 parts. Therefore, yellow paint represents 38\frac{3}{8} of the total mixture.
To find the amount of one component in a given total volume, we must find the part-to-whole ratio of that component to the total mixture.
2
Multiply the fraction representing yellow paint by the total desired volume of green paint.
38×40=3×5=15\frac{3}{8} \times 40 = 3 \times 5 = 15 gallons.
Multiplying the part-to-whole ratio by the total volume gives the specific volume of yellow paint needed.

Anahtar Kavram

Solving part-to-whole ratio problems by summing the ratio parts to find the total parts, then multiplying the corresponding fraction by the total quantity.
Soru 48Soru

A deep space satellite transmits data to a ground station at a constant rate of 1.61.6 megabits per second. The transmitted data consists of actual scientific data and protocol overhead. The protocol overhead accounts for 25%25\% of the total transmitted bits, meaning the actual scientific data constitutes only 75%75\% of the total transmitted bits. The ground station needs to receive 55 scientific data files, each with a size of 1.081.08 gigabytes. How many hours will it take to transmit all 55 files? (Given that 1textbyte=8textbits1\\text{ byte} = 8\\text{ bits}, 1textmegabit=106textbits1\\text{ megabit} = 10^6\\text{ bits}, and 1textgigabyte=109textbytes1\\text{ gigabyte} = 10^9\\text{ bytes}.)

Cevabı ve açıklamayı göster

Cevap: 10

Cevap

It will take 10 hours to transmit all 5 files.
The correct answer is 10. To find this, first calculate the total size of the scientific files: 5 files * 1.08 gigabytes per file = 5.4 gigabytes. Convert this to bytes: 5.4 * 10^9 bytes. Convert bytes to bits: 5.4 * 10^9 * 8 = 43.2 * 10^9 bits. Since protocol overhead is 25%, the scientific data is 75% of the total transmitted bits, so the total bits transmitted is 43.2 * 10^9 / 0.75 = 57.6 * 10^9 bits. The transmission rate is 1.6 megabits per second, or 1.6 * 10^6 bits per second. The transmission time in seconds is 57.6 * 10^9 / (1.6 * 10^6) = 36,000 seconds. Converting seconds to hours: 36,000 / 3,600 = 10 hours.

Adım Adım Çözüm

1
Calculate the total size of the scientific files in gigabytes.
5.45.4 gigabytes
To find the total amount of scientific data that must be received.
2
Convert the total scientific data size from gigabytes to bytes and then to bits.
43.2times10943.2 \\times 10^9 bits
The transmission rate is given in megabits per second, so the data size must be converted to bits for unit consistency. Since 1textGB=109textbytes1\\text{ GB} = 10^9\\text{ bytes} and 1textbyte=8textbits1\\text{ byte} = 8\\text{ bits}, we have 5.4times109times8=43.2times1095.4 \\times 10^9 \\times 8 = 43.2 \\times 10^9 bits.
3
Calculate the total number of bits transmitted, including protocol overhead.
57.6times10957.6 \\times 10^9 bits
Since protocol overhead is 25%25\%, the scientific data is only 75%75\% of the total bits transmitted. Thus, we divide the scientific bits by 0.750.75 to find the total bits transmitted: frac43.2times1090.75=57.6times109\\frac{43.2 \\times 10^9}{0.75} = 57.6 \\times 10^9 bits.
4
Calculate the transmission time in seconds.
36,00036,000 seconds
Divide the total bits by the transmission rate in bits per second (1.6textMbps=1.6times1061.6\\text{ Mbps} = 1.6 \\times 10^6 bits per second): frac57.6times1091.6times106=36,000\\frac{57.6 \\times 10^9}{1.6 \\times 10^6} = 36,000 seconds.
5
Convert the transmission time from seconds to hours.
1010 hours
Since there are 3,6003,600 seconds in one hour, divide the total seconds by 3,6003,600: frac36,0003,600=10\\frac{36,000}{3,600} = 10.

Anahtar Kavram

Multi-step dimensional analysis and compound rate conversions incorporating percentage overhead

Alternatif Yöntem

Instead of converting units step-by-step, dimensional analysis can be set up as a single product of conversion factors: 5 files * (1.08 GB / 1 file) * (10^9 bytes / 1 GB) * (8 bits / 1 byte) * (1 total bit / 0.75 scientific bits) * (1 second / 1.6 * 10^6 bits) * (1 hour / 3600 seconds) = 10 hours.
Tahmini Süre:3m 0s
Soru 49Soru

A study by a wildlife biologist shows that the population of a certain species of songbird in a state park increases by 8%8\% of its previous year's population each year. The initial population of the songbirds in the park was 150150. If tt represents the number of years since the study began, which of the following functions best models the population of songbirds, P(t)P(t), after tt years?

Cevabı ve açıklamayı göster

Cevap: P(t)=150(1.08)tP(t) = 150(1.08)^t

Cevap

The correct function is P(t)=150(1.08)tP(t) = 150(1.08)^t.
The correct answer is the function showing the initial value of 150150 multiplied by the growth factor 1.081.08 raised to the power of tt. Since the population increases by a constant percentage (8%8\%) each year, the growth is exponential. The general form of an exponential growth model is P(t)=P0(1+r)tP(t) = P_0(1 + r)^t, where P0=150P_0 = 150 is the initial value and r=0.08r = 0.08 is the growth rate. Substituting these values gives P(t)=150(1.08)tP(t) = 150(1.08)^t.

Adım Adım Çözüm

1
Identify the initial value of the population.
The initial population of songbirds is 150150.
The initial value represents the population when t=0t = 0, which corresponds to the coefficient P0P_0 in the exponential growth model.
2
Determine the growth rate and calculate the growth factor.
The population increases by 8%8\% each year, so the growth rate r=0.08r = 0.08, and the growth factor is 1+r=1+0.08=1.081 + r = 1 + 0.08 = 1.08.
An increase by a constant percentage each year represents exponential growth, where the growth factor is 1+r1 + r.
3
Formulate the exponential growth function.
P(t)=150(1.08)tP(t) = 150(1.08)^t
An exponential growth model is written in the form P(t)=P0(b)tP(t) = P_0(b)^t, where P0P_0 is the initial value and bb is the growth factor.

Anahtar Kavram

Distinguishing between linear and exponential growth, and constructing exponential models from a percent growth rate.
Soru 50Soru

The table below shows the daily high temperatures, in degrees Celsius, recorded in a city over a 99-day period.

Daily High Temperature (°C)Number of Days
181833
191911
202022
212133

Based on the table, what was the median daily high temperature, in degrees Celsius, for the 99-day period?

Cevabı ve açıklamayı göster

Cevap: 20

Cevap

The median daily high temperature for the 9-day period is 2020 °C.
To find the median daily high temperature, we first sum the frequencies to find the total number of days: 3+1+2+3=93 + 1 + 2 + 3 = 9. Because 99 is an odd number, the median is the middle value, which is the 55 th value when the data points are ordered from least to greatest. The first 33 values are 1818, the 44 th value is 1919, and the 55 th and 66 th values are 2020. Therefore, the 55 th value in the ordered list is 2020.

Adım Adım Çözüm

1
Determine the total number of observations (days) in the data set.
99 days
To find the position of the median value, we must first calculate the total number of data points by adding the frequencies: 3+1+2+3=93 + 1 + 2 + 3 = 9.
2
Find the position of the median in the ordered data set.
55 th position
For an odd number of observations nn, the median is located at the n+12\frac{n+1}{2} position. With n=9n = 9, this corresponds to the 9+12=5\frac{9+1}{2} = 5 th value.
3
Identify the temperature at the 55 th position using the frequency table.
2020
Listing the temperatures in ascending order gives: 18,18,1818, 18, 18 (positions 1–3), 1919 (position 4), and 20,2020, 20 (positions 5–6). The value at the 55 th position is 2020.

Anahtar Kavram

Finding the median of a frequency distribution
Soru 51Soru

A library administrator tracked a sample of 120120 books checked out last week, categorizing them by genre (fiction or nonfiction) and format (print or audiobook). The results are summarized in the table below.

FormatFictionNonfiction
Print45453535
Audiobook15152525

Of the books in the sample that were checked out as audiobooks, what fraction were fiction?

Cevabı ve açıklamayı göster

Cevap: 0.375

Cevap

The fraction of audiobooks that were fiction is 3/8 (which can also be gridded as the decimal .375).
To find the fraction of audiobooks that were fiction, find the total number of audiobooks in the sample by adding the values in the audiobook row: 15+25=4015 + 25 = 40. Next, find the number of fiction audiobooks, which is 1515. The fraction of audiobooks that were fiction is the ratio of these two values: 1540\frac{15}{40}, which simplifies to 38\frac{3}{8} (or 0.3750.375 in decimal form).

Adım Adım Çözüm

1
Calculate the total number of audiobooks in the sample.
The total number of audiobooks is 15+25=4015 + 25 = 40.
The question asks for the fraction of books *that were checked out as audiobooks*, which means the denominator of our fraction must be the total number of audiobooks.
2
Identify the number of fiction audiobooks in the sample.
There are 1515 fiction audiobooks.
The question asks what fraction of the audiobooks were *fiction*, so the numerator must be the number of books that are both audiobooks and fiction.
3
Write and simplify the fraction representing the conditional probability.
1540=38\frac{15}{40} = \frac{3}{8}
Divide the target number of books (15) by the total number of audiobooks (40). Simplify by dividing the numerator and the denominator by their greatest common divisor, which is 5.

Anahtar Kavram

Conditional Probability from a Two-Way Table
Tahmini Süre:1m 15s
Soru 52Soru

A digital music playlist contains only rock songs and pop songs. At the beginning of the month, 60%60\% of the songs in the playlist were rock songs. During the month, the number of rock songs in the playlist increased by 10%10\%, and the number of pop songs in the playlist increased by 35%35\%. If there were 120120 rock songs in the playlist at the beginning of the month, what percent of the songs in the playlist at the end of the month were pop songs?

Cevabı ve açıklamayı göster

Cevap: 45

Cevap

The percent of the songs in the playlist at the end of the month that were pop songs is 45.
To find the final percentage of pop songs, we first determine the initial number of songs. Since 120120 rock songs represent 60%60\% of the playlist, the initial total is 120/0.60=200120 / 0.60 = 200 songs. This means there are 200120=80200 - 120 = 80 pop songs initially. During the month, the rock songs increase by 10%10\%, yielding 120×1.10=132120 \times 1.10 = 132 songs. The pop songs increase by 35%35\%, yielding 80×1.35=10880 \times 1.35 = 108 songs. The final total number of songs is 132+108=240132 + 108 = 240. The final percentage of pop songs is 108240×100=45%\frac{108}{240} \times 100 = 45\%. Thus, the correct value to grid in is 45.

Adım Adım Çözüm

1
Determine the initial total number of songs and initial pop songs.
The initial total number of songs is 200, and the initial number of pop songs is 80.
Since 120 rock songs represent 60% of the playlist, the initial total is 120 / 0.60 = 200. The remaining songs are pop songs: 200 - 120 = 80.
2
Calculate the updated number of rock songs and pop songs after the percentage increases.
The final rock song count is 132, and the final pop song count is 108.
The number of rock songs increased by 10%, which is 120 * 1.10 = 132. The number of pop songs increased by 35%, which is 80 * 1.35 = 108.
3
Calculate the final total number of songs and the final percentage of pop songs.
The final total is 240 songs, and the final pop song percentage is 45%.
The final total is 132 + 108 = 240. The final pop song percentage is (108 / 240) * 100 = 45%.

Anahtar Kavram

Calculating absolute quantities from initial percentages, applying percentage increases to separate groups, and finding a new conditional percentage based on the final total.
Soru 53Soru

An industrial printing press uses ink at a constant rate of 0.050.05 milliliters per square centimeter of printed paper. The press prints a continuous roll of paper that is 4040 centimeters wide at a constant speed of 22 meters per second. At this rate, how many liters of ink does the press use during 11 hour of continuous printing?

Cevabı ve açıklamayı göster

Cevap: 1440

Cevap

1440
The correct answer is 1440. First, convert the speed of the paper from meters per second to centimeters per second: 2 m/s×100 cm/m=200 cm/s2 \text{ m/s} \times 100 \text{ cm/m} = 200 \text{ cm/s}. Next, find the rate at which the paper surface area is printed: 40 cm×200 cm/s=8,000 cm2/s40 \text{ cm} \times 200 \text{ cm/s} = 8,000 \text{ cm}^2/\text{s}. Multiply this by the ink usage rate to find milliliters of ink per second: 8,000 cm2/s×0.05 mL/cm2=400 mL/s8,000 \text{ cm}^2/\text{s} \times 0.05 \text{ mL/cm}^2 = 400 \text{ mL/s}. Since there are 3,6003,600 seconds in 11 hour, the press uses 400 mL/s×3,600 s=1,440,000 mL400 \text{ mL/s} \times 3,600 \text{ s} = 1,440,000 \text{ mL} of ink per hour. Finally, convert milliliters to liters: 1,440,000 mL÷1,000 mL/L=1,4401,440,000 \text{ mL} \div 1,000 \text{ mL/L} = 1,440 liters.

Adım Adım Çözüm

1
Convert the speed of the paper from meters per second to centimeters per second.
200 cm/s200 \text{ cm/s}
To align the speed unit with the paper width unit (40 cm40 \text{ cm}).
2
Calculate the surface area of paper printed per second.
8,000 cm2/s8,000 \text{ cm}^2/\text{s}
Multiply the width of the paper (40 cm40 \text{ cm}) by the converted speed (200 cm/s200 \text{ cm/s}).
3
Calculate the volume of ink used per second in milliliters.
400 mL/s400 \text{ mL/s}
Multiply the area printed per second (8,000 cm2/s8,000 \text{ cm}^2/\text{s}) by the ink consumption rate (0.05 mL/cm20.05 \text{ mL/cm}^2).
4
Convert the ink volume rate from per second to per hour.
1,440,000 mL/h1,440,000 \text{ mL/h}
Multiply the rate per second by 3,6003,600, since there are 3,6003,600 seconds in 11 hour.
5
Convert the final volume from milliliters to liters.
1440
Divide the total milliliters (1,440,0001,440,000) by 1,0001,000, since 11 liter is equal to 1,0001,000 milliliters.

Anahtar Kavram

Multi-step dimensional analysis and compound unit conversion (length, area, volume, and time).
Soru 54Soru

A printer prints 2424 pages in 33 minutes. At this constant rate, how many pages can the printer print in 1010 minutes?

Cevabı ve açıklamayı göster

Cevap: 80

Cevap

80
The correct answer is 80. The printer's rate of printing is determined by dividing 24 pages by 3 minutes, which is 8 pages per minute. Multiplying this rate of 8 pages per minute by 10 minutes gives a total of 80 pages printed.

Adım Adım Çözüm

1
Calculate the unit rate of pages printed per minute.
24÷3=824 \div 3 = 8 pages per minute
Dividing the total pages by the total minutes gives the constant rate of printing.
2
Multiply the unit rate by the new amount of time.
8×10=808 \times 10 = 80 pages
Multiplying the pages per minute by 10 minutes gives the total number of pages printed in that time.

Anahtar Kavram

Calculating and applying a unit rate to solve a proportion.
Soru 55Soru

A town's population was 12,00012,000 in the year 20102010. Since 20102010, the population of the town has increased by a constant amount of 350350 people each year. Based on this information, what was the population of the town in the year 20182018?

Cevabı ve açıklamayı göster

Cevap: 14800

Cevap

14,800
The population starts at 12,00012,000 in 20102010 and grows linearly by 350350 people per year. The number of years from 20102010 to 20182018 is 20182010=82018 - 2010 = 8 years. The total increase in population is 350×8=2,800350 \times 8 = 2,800 people. Adding this to the initial population of 12,00012,000 gives a total population of 12,000+2,800=14,80012,000 + 2,800 = 14,800 in the year 20182018.

Adım Adım Çözüm

1
Calculate the number of years that passed between 20102010 and 20182018.
88 years
To determine the total population growth, we need the elapsed time in years.
2
Calculate the total population growth over this 88-year period.
2,8002,800 people
Since the growth is linear, the total growth is the constant annual rate of change multiplied by the number of years.
3
Add the total population growth to the initial population from 20102010.
14,80014,800
The population in 20182018 is the initial population plus the total growth over the 88-year period.

Anahtar Kavram

Linear growth represents a quantity that increases by a constant amount per unit of time.
Soru 56Soru

An agricultural researcher categorized a sample of 150150 tomato plants by their watering schedule (daily or weekly) and their fruit yield (high yield or average yield). The results are summarized in the table below.

Watering ScheduleHigh YieldAverage YieldTotal
Daily626218188080
Weekly282842427070
Total90906060150150

Given that a tomato plant selected at random from the sample produced a high yield of fruit, what is the probability that the plant had a weekly watering schedule?

Cevabı ve açıklamayı göster

Cevap: 1445\frac{14}{45}

Cevap

The correct answer is fourteen-forty-fifths (14/45). Given that the plant has a high yield, the sample space is restricted to the 90 plants in the High Yield column. Out of these 90 plants, 28 were on a weekly watering schedule, resulting in a probability of 28/90, which simplifies to 14/45.
To find the conditional probability that a tomato plant had a weekly watering schedule given that it produced a high yield of fruit, restrict the denominator to the total number of high-yield plants, which is 90. The numerator is the number of plants that meet both conditions (weekly watering and high yield), which is 28. The probability is 28/90, which simplifies to 14/45.

Adım Adım Çözüm

1
Identify the condition specified in the question stem to determine the subset of data to consider.
The condition is 'given that a tomato plant ... produced a high yield of fruit'. Thus, we restrict our focus to the 'High Yield' column.
This establishes the denominator for the conditional probability calculation.
2
Find the total number of plants in the 'High Yield' column (denominator) and the number of those plants that had a weekly watering schedule (numerator).
Total high-yield plants = 90. High-yield plants with a weekly watering schedule = 28.
These represent the total possible outcomes and the favorable outcomes within the restricted sample space.
3
Calculate and simplify the fraction representing the conditional probability.
Probability=2890=1445.Probability = \frac{28}{90} = \frac{14}{45}.
Expressing the final ratio in its simplest fractional form to match the standard exam options.

Anahtar Kavram

Two-Way Tables and Conditional Probability
Tahmini Süre:1m 30s
Soru 57Soru

A study of 180180 college students categorized them by their major field of study (STEM or Humanities) and whether they participate in undergraduate research. The table below shows the partial results of the study, where aa, bb, cc, and dd represent the number of students in each category.

MajorParticipates in ResearchDoes Not Participate in ResearchTotal
STEMaabb110110
Humanitiesccdd7070
Total8080100100180180

Given that a student selected at random is a Humanities major, the probability that the student participates in undergraduate research is 37\frac{3}{7}. If a student who participates in undergraduate research is selected at random, what is the probability that the student is a STEM major?

Cevabı ve açıklamayı göster

Cevap: 58\frac{5}{8}

Cevap

The correct probability is 58\frac{5}{8}.
To find the probability that a student is a STEM major given they participate in undergraduate research, we first determine the missing values in the table. The total number of Humanities majors is 7070. Since the probability that a Humanities major participates in research is 37\frac{3}{7}, the number of Humanities majors in research is c=37×70=30c = \frac{3}{7} \times 70 = 30. Using the research column total, the number of STEM majors in research is a=80c=8030=50a = 80 - c = 80 - 30 = 50. The probability that a student is a STEM major given that they participate in research is the ratio of STEM research participants to total research participants: aa+c=5080=58\frac{a}{a+c} = \frac{50}{80} = \frac{5}{8}.

Adım Adım Çözüm

1
Find the number of Humanities majors who participate in research (cc).
c=30c = 30
The table shows there are 7070 Humanities majors in total. We are given that the probability of a Humanities major participating in research is 37\frac{3}{7}. Therefore, c70=37\frac{c}{70} = \frac{3}{7}, which simplifies to c=30c = 30.
2
Find the number of STEM majors who participate in research (aa).
a=50a = 50
The total number of students who participate in research is 8080. Since a+c=80a + c = 80 and c=30c = 30, we have a+30=80a + 30 = 80, which means a=50a = 50.
3
Calculate the conditional probability that a student who participates in research is a STEM major.
58\frac{5}{8}
We want to find the probability of selecting a STEM major given that the student participates in research. This is the ratio of STEM majors who participate in research (a=50a = 50) to the total number of students who participate in research (8080). The probability is 5080=58\frac{50}{80} = \frac{5}{8}.

Anahtar Kavram

Conditional Probability in Two-Way Tables
Soru 58Soru

The value of a financial asset, V(t)V(t), in dollars, is modeled as a function of time tt, in years, for 0t40 \le t \le 4. The growth of the asset's value is described by two different models over this period:

- For 0t20 \le t \le 2, the value of the asset increases by a constant percentage of r%r\% per year.
- For 2t42 \le t \le 4, the value of the asset increases by a constant amount of dd dollars per year.

At t=0t = 0, the value of the asset is 100100 dollars, and at t=1t = 1, the value of the asset is 120120 dollars. If the average rate of change of the asset's value from t=0t = 0 to t=4t = 4 is 2525 dollars per year, what is the value of the asset, in dollars, at t=3t = 3?

Cevabı ve açıklamayı göster

Cevap: 172

Cevap

172
To find the value of the asset at t=3t = 3, we first determine its value at t=2t = 2 using the exponential growth model. Since the value increases by a constant percentage from t=0t=0 to t=2t=2, the value is modeled by V(t)=V(0)×(1+r100)tV(t) = V(0) \times (1 + \frac{r}{100})^t. Given V(0)=100V(0) = 100 and V(1)=120V(1) = 120, the annual growth factor is 1.21.2. Thus, V(2)=100×(1.2)2=144V(2) = 100 \times (1.2)^2 = 144 dollars.

Next, the linear growth from t=2t = 2 to t=4t = 4 is modeled by V(t)=V(2)+d(t2)=144+d(t2)V(t) = V(2) + d(t - 2) = 144 + d(t - 2), which gives V(4)=144+2dV(4) = 144 + 2d dollars. The average rate of change of the asset's value from t=0t = 0 to t=4t = 4 is 2525 dollars per year, so we set up the equation: V(4)V(0)4=25    (144+2d)1004=25\frac{V(4) - V(0)}{4} = 25 \implies \frac{(144 + 2d) - 100}{4} = 25. Solving for dd gives d=28d = 28 dollars per year. Finally, we evaluate the value at t=3t = 3: V(3)=144+28(32)=172V(3) = 144 + 28(3 - 2) = 172 dollars.

Adım Adım Çözüm

1
Identify the growth model for 0t20 \le t \le 2 and write the corresponding equation using the initial values.
Since the value increases by a constant percentage each year, the growth is exponential: V(t)=V(0)×(1+r100)tV(t) = V(0) \times (1 + \frac{r}{100})^t. Given V(0)=100V(0) = 100 and V(1)=120V(1) = 120, we have 120=100(1+r100)1    1+r100=1.2120 = 100(1 + \frac{r}{100})^1 \implies 1 + \frac{r}{100} = 1.2.
Establishing the exponential model allows us to find the growth factor and calculate the value of the asset at the boundary of the two models (t=2t = 2).
2
Calculate the value of the asset at t=2t = 2 using the exponential growth model.
V(2)=100×(1.2)2=144V(2) = 100 \times (1.2)^2 = 144 dollars.
The value at t=2t = 2 serves as the initial value for the linear growth model in the second interval.
3
Write the growth model for the interval 2t42 \le t \le 4.
The growth is linear, so V(t)=V(2)+d(t2)=144+d(t2)V(t) = V(2) + d(t - 2) = 144 + d(t - 2) for t2t \ge 2. At t=4t = 4, the value is V(4)=144+2dV(4) = 144 + 2d dollars.
Expressing the value at t=4t = 4 in terms of the constant rate dd allows us to use the average rate of change information to solve for dd.
4
Set up the equation for the average rate of change over the entire interval from t=0t = 0 to t=4t = 4 and solve for dd.
The average rate of change is given by V(4)V(0)40=25\frac{V(4) - V(0)}{4 - 0} = 25. Substituting the values, we get (144+2d)1004=25    44+2d4=25    44+2d=100    2d=56    d=28\frac{(144 + 2d) - 100}{4} = 25 \implies \frac{44 + 2d}{4} = 25 \implies 44 + 2d = 100 \implies 2d = 56 \implies d = 28 dollars per year.
The average rate of change relates the final value at t=4t=4 to the initial value at t=0t=0, enabling us to determine the linear rate of change dd.
5
Calculate the value of the asset at t=3t = 3 using the linear model.
V(3)=V(2)+d(32)=144+28(1)=172V(3) = V(2) + d(3 - 2) = 144 + 28(1) = 172 dollars.
Substituting t=3t = 3 into the linear growth model yields the final requested value.

Anahtar Kavram

Linear and Exponential Growth

Alternatif Yöntem

Instead of setting up the linear equation from t=2t = 2 to t=4t = 4, we can write V(4)V(4) directly as V(0)+4×25=200V(0) + 4 \times 25 = 200 dollars using the definition of average rate of change. Since V(2)=144V(2) = 144 dollars, the total change over the linear interval [2,4][2, 4] is 200144=56200 - 144 = 56 dollars. Because the growth is linear during this interval, the change over one year (from t=2t = 2 to t=3t = 3) must be exactly half of the change over two years (from t=2t = 2 to t=4t = 4). Thus, the increase from t=2t = 2 to t=3t = 3 is 56/2=2856 / 2 = 28 dollars, yielding V(3)=144+28=172V(3) = 144 + 28 = 172 dollars.
Tahmini Süre:3m 0s
Soru 59Soru

A biologist measures the heights, in centimeters, of five seedlings in a laboratory. The heights are 1212, 1515, 88, 2121, and 1414. What is the range, in centimeters, of these heights?

Cevabı ve açıklamayı göster

Cevap: 13

Cevap

13
To find the range of a dataset, subtract the minimum value from the maximum value. In the given dataset of seedling heights (1212, 1515, 88, 2121, and 1414), the maximum height is 2121 centimeters and the minimum height is 88 centimeters. Calculating the difference gives 218=1321 - 8 = 13 centimeters.

Adım Adım Çözüm

1
Identify the maximum and minimum values in the dataset.
The maximum value is 2121 and the minimum value is 88.
The range is defined as the difference between the largest (maximum) and smallest (minimum) values in a data distribution.
2
Subtract the minimum value from the maximum value to calculate the range.
218=1321 - 8 = 13
Subtracting the minimum value of 88 from the maximum value of 2121 yields the range of the dataset.

Anahtar Kavram

The range of a dataset measures the spread of the data and is calculated by subtracting the minimum value from the maximum value.
Soru 60Soru

The list below shows the number of packages delivered to a local business on each of 88 business days:

1,2,2,3,5,6,7,101, 2, 2, 3, 5, 6, 7, 10

What is the median number of packages delivered on these days?

Cevabı ve açıklamayı göster

Cevap: 4

Cevap

4
The correct answer is the median value of 44. The list contains 88 values already sorted in ascending order: 1,2,2,3,5,6,7,101, 2, 2, 3, 5, 6, 7, 10. Because the number of values is even, the median is the average of the two middle values (the 44 th and 55 th values, which are 33 and 55). The average is calculated as 3+52=4\frac{3 + 5}{2} = 4.

Adım Adım Çözüm

1
Identify the two middle terms of the ordered dataset.
The two middle values in the ordered list of 8 numbers are the 4th term, which is 33, and the 5th term, which is 55.
Since the dataset has an even number of values (88), the median is the average of the two middle terms.
2
Calculate the average of the two middle terms.
3+52=82=4\frac{3 + 5}{2} = \frac{8}{2} = 4
Finding the mean of these two middle values yields the median of the entire dataset.

Anahtar Kavram

Calculating the median of a dataset with an even number of values
Tahmini Süre:45s
ÖncekiSayfa 3 / 9Sonraki