Solving Problems involving Proportional Reasoning

The ratio to the number boys to the number of girls in a band class is 9 to 10. There are 20 girls in the band class.

How many boys are in the band class?

• 18

• 21

• 39

• 110

In Austin, Texas, 5 bats ate 15 grams of insects in one night. At this rate, how many grams of insects could 25 bats eat in one night?

A large bucket contained 30 gallons of water. Water leaked out of the bucket at a rate of 3 gallons every 2 days.

At this rate, how many days did it take for all 30 gallons of water to leak out of the bucket?

• 35 days

• 90 days

• 10 days

• 20 days

Mrs. Malyemezian mixed 4 gal of red paint with every 6 gal of blue paint in order to make purple paint. Which ratio of gallons of red paint to gallons of blue paint will make the same shade of purple paint?

• 12:18

• 5:7

• 8:30

• 12:8

Camden rode his bike to school on 14 of the 20 school days in November. Which value is equivalent to the fraction of the school days in November that Camden rode his bike to school?

• 70%

• 0.07

• 0.142

• 56%

A coat is discounted 60% off its regular price. Which value is equivalent to 60%?

• 0.006

• 60

The list shows the number of viewers of an online music video each day for 4 consecutive days.

5, 35, 245, 1,715

By what factor did the number of viewers change each day from the first day to the fourth day?

• 7

• 12,000

• 2,401

• 30

A certain type of brass contains 65% copper. How many pounds of copper are contained in 120 pounds of the brass?

• 7%

• 35%

• 20%

• 13%