IMSA Ratios, Proportions, and Percentages 2 — Questions and Answers
Question 1: The ratio of red to blue marbles is 5:3. If there are 40 red marbles, how many blue marbles are there?
- 20
- 24 (Correct answer)
- 16
- 32
Correct answer: 24
Using the proportion 5/3 = 40/x, cross-multiplying gives x = 24 blue marbles.
Question 2: A salesperson earns a 6% commission on sales. How much commission does she earn on $4,500 in sales?
- $270 (Correct answer)
- $225
- $300
- $240
Correct answer: $270
Commission = 0.06 × 4,500 = $270.
Question 3: Two quantities are in the ratio 7:9. If the larger quantity is 63, what is the smaller?
- 42
- 49 (Correct answer)
- 56
- 45
Correct answer: 49
Using the proportion 7/9 = x/63, cross-multiplying gives x = 49.
Question 4: A school's enrollment increased from 800 to 920 students. What is the percent increase?
- 12%
- 15% (Correct answer)
- 18%
- 10%
Correct answer: 15%
Percent increase = (920 − 800) / 800 × 100 = 120/800 × 100 = 15%.
Question 5: If 3/4 of a number is 60, what is 25% of the same number?
- 15
- 20 (Correct answer)
- 25
- 30
Correct answer: 20
The number is 60 ÷ (3/4) = 80, and 25% of 80 = 0.25 × 80 = 20.
Question 6: A map uses a scale of 1 inch = 25 miles. If two cities are 3.5 inches apart on the map, what is the actual distance?
- 75 miles
- 87.5 miles (Correct answer)
- 100 miles
- 62.5 miles
Correct answer: 87.5 miles
Actual distance = 3.5 × 25 = 87.5 miles.
Question 7: After a 15% increase followed by a 10% decrease, what is the net percentage change from the original value?
- 3.5% increase (Correct answer)
- 5% increase
- 3.5% decrease
- 5% decrease
Correct answer: 3.5% increase
Multiplying the factors: 1.15 × 0.90 = 1.035, which represents a 3.5% net increase.
IMSA Ratios, Proportions, and Percentages 2
The ratio of red to blue marbles is 5:3.
If there are 40 red marbles, how many blue marbles are there?