WRITING PROPORTION FROM WORD PROBLEMS

Write a proportion that could be used to solve for each variable, then solve. Round to the nearest hundredth.

Problem 1 :

If there are 8 pencils in 2 boxes, how many pencils will fit into 5 boxes?

Solution:

Let x be the pencils.

8 : 2 = x : 5

2x = 40

x = 40/2

x = 20 pencils

So, 20 pencils will fit into 5 boxes.

Problem 2 :

If 5 quarts of juice costs $6.25, how many quarts of juice can you buy with $8.75?

Solution:

Let x be the quarts of juice.

5 : 6.25 = x : 8.75

6.25x = 5 × 8.75

6.25x = 43.75

x = 43.75/6.25

x = 7 quarts of juice

So, 7 quarts of juice can you buy with $8.75.

Problem 3 :

If there are 3.28 feet in a meter, how many feet are in the 110 meter dash?

Solution:

Let x be the feet.

3.28 : 1 = x : 110

x = 3.28 × 110

x = 360.8 feet

So, 360.8 feet are in the 110 meter dash.

Problem 4 :

A photograph is 3 inches wide by 5 inches long. If the photograph is enlarged so that the length is 7 inches, how wide is the enlarged photo?

Solution:

Let x be the wide.

3 : 5 = x : 7

5x = 21

x = 21/5

x = 4.2 inches

So, 4.2 inches wide is the enlarged photo.

Problem 5 :

If 1 pint of paint is need to paint a square that is 5 feet on each side, how many pints are needed to paint a square that is 9 feet on each side?

Solution:

Let x be the pints.

1 : 5 = x : 9

5x = 9

x = 9/5

x = 1.8 pints

So, 1.8 pints are needed.

Problem 6 :

The world's largest baseball bat is 120 feet long. If there are 30.28 centimeters in a foot, find the length of the bat in centimeters.

Solution:

Let x be the length.

120 : 1 = x : 30.28

x = 120 × 30.28

x = 3633.6 cm

So, length of the bat in 3633.6 centimeters.