IAAT Ratios and Proportional Reasoning 2

Question 1

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

Accepted Answer

a × d = b × c

Answer

In any proportion a/b = c/d, the cross-products are equal: a × d = b × c.

Question 2

A store sells 3 apples for $1.20. At this rate, how much do 10 apples cost?

Accepted Answer

$4.00

Answer

Unit price = $1.20 ÷ 3 = $0.40 per apple; 10 × $0.40 = $4.00.

Question 3

The ratio of red marbles to blue marbles is 2:7. If there are 63 blue marbles, how many red marbles are there?

Accepted Answer

18

Answer

If 7 parts = 63, then 1 part = 9, so 2 parts (red) = 18.

Question 4

Which table of values shows a proportional relationship?

Accepted Answer

x: 1,2,3 | y: 2,4,6

Answer

In x: 1,2,3 | y: 2,4,6, the ratio y/x = 2 for all pairs, confirming proportionality.

Question 5

If 12 workers can complete a job in 8 days, how many days will 6 workers need to complete the same job?

Accepted Answer

16 days

Answer

This is inverse proportion: 12 × 8 = 6 × d, so d = 96 ÷ 6 = 16 days.

IAAT - Iowa Algebra Aptitude Test Practice Test