Practice!

Sample Problem

The ratio of the amount of money Ann receives to the amount of money Frank receives is 4:7. If Ann receives $300 less than Frank, how much money does Frank receive?

$

Solution

Solution 1:

Set the number of Ann’s money as 4 units and Frank’s money as 7 units. Then, the difference between Frank’s money and Ann’s money is (7 – 4 = 3) units. Then,

3 units = 300

1 unit = 300 ÷ 3 = 100

7 units = 7 × 100 = 700

Thus, Frank receives $700

Solution 2:

Also, we can use the method of finding an equivalent ratio to find the number of each part.

We can make a chart.

Ann Frank Difference
4 7 7 - 4 = 3
4 × a 7 × a 3 × a = 300

From the chart above we know that, a = 300 ÷ 3 = 100

Thus,

Frank: 7 × a = 7 × 100 = 700