IMSA Ratios, Proportions, and Percentages 3

Question 1

If 40% of a number equals 28, what is the number?

Accepted Answer

70

Answer

Setting up 0.40x = 28 and dividing both sides by 0.40 gives x = 70.

Question 2

In a proportion a/b = c/d, which of the following must always be true?

Accepted Answer

a × d = b × c

Answer

The cross-multiplication property of proportions states that a × d = b × c.

Question 3

A student scored 72 out of 90 on a test. What percentage did the student score?

Accepted Answer

80%

Answer

72 ÷ 90 × 100 = 0.80 × 100 = 80%.

Question 4

Two numbers are in the ratio 4:7. Their sum is 99. What is the larger number?

Accepted Answer

63

Answer

Let the numbers be 4x and 7x; then 4x + 7x = 99, so x = 9 and the larger number is 7 × 9 = 63.

Question 5

A tank is 40% full. After adding 30 liters, it becomes 70% full. What is the total capacity of the tank?

Accepted Answer

100 liters

Answer

The 30 liters added represents 70% − 40% = 30% of the capacity, so capacity = 30 ÷ 0.30 = 100 liters.

IMSA - Intermediate Math Skill Assesment Practice Test