Proportions in Word Problems

Proportion Word Problems

• If you can buy one can of pineapple chunksfor $2 then how many can you buy with $10?– First set up a proportion then solve for your

variable.– Remember proportions are two equivalent ratios

set equal to each other.– 1 can = x $2 $10

Solving the proportion

• 1 can = x cans $2 $10

• 1(10) = 2x• 10 = 2x• 10 = 2x 2 2• 5 = x: You can buy 5 cans with $10.

Proportion Word Problems

• Ming was planning a trip to Western Samoa. Before going, she did some research and learned that the exchange rate is 6 Tala for $2. How many Tala would she get if she exchanged $6?– First set up a proportion then solve for your variable.– Remember proportions are two equivalent ratios set

equal to each other.– 6 Tala = x Tala $2 $6

Solving the proportion

• 6 Tala = x Tala $2 $6

• 6(6) = 2x• 36 = 2x• 36 = 2x 2 2• 18 = x: She would get 18 Tala.

Try one on your own…

• Jasmine bought 32 kiwi fruit for $16. How many kiwi can Jasmine buy if she only had $4?– First set up a proportion then solve for your

variable.– Remember proportions are two equivalent ratios

set equal to each other.

And another…

• Jenny was planning a trip to the United Arab Emirates. Before going, she did some research and learned that the exchange rate is 4 Dirhams for every $1. How many Dirhams would she get if she exchanged $5?

And one more…

• Shawna reduced the size of a rectangle to a height of 2 in. What is the new width if it was originally 24 in wide and 12 in tall?

Ex 1 Set up proportions

Two machines can complete 7 tasks every 3 days. Let t represent the number of tasks these machines can complete in a 30-day month. Write as a proportion.

7

3

tasks

days

30

t tasks

days

Ex 3 Set up proportions

Four pounds of grass seed will cover 100 sq ft. Let p represent the number of pounds of seed needed to cover 780 sq ft. Write as a proportion.

4

100

lbs

sq ft

780

p lbs

sq ft

Ex 4: On a road map 3 inches represents 40 miles. If two cities are 10 inches apart on the map, how many miles is it from one to the other?

miles3

1133

3" 10"

40mi d

inches

miles 3 400d

Ex 5: The ratio of boys to girls on the swim team is 5 to 4. How many girls are on the team if there are 65 boys?

boys

girls

5 65

4 x

5 260x

52x girls