Tommy and Jeremy had $139 and $113 respectively. Each of them bought a skirt and a shirt at the same price. The cost of the skirt was 4 times as much as the shirt. In the end, Tommy had 3 times as much money as Jeremy. What was the difference between the cost of the shirt and the skirt?

	Tommy	Jeremy	Difference
Before	$139	$113	$26
Change	- 5 p	- 5 p
After	3 u	1 u	2 u

Since Tommy and Jeremy bought the same items at the same price, the difference in the amounts they had remains unchanged at first and in the end.

3 u - 1 u = 139 - 113
2 u = 26

1 u = 26 ÷ 2 = 13

Cost of 1 skirt = 4 p
Cost of 1 shirt = 1 p

Total cost of 1 skirt and 1 shirt
= 4 p + 1 p
= 5 p

5 p = 113 - 13
5 p = 100

1 p = 100 ÷ 5 = 20

Difference in the cost between the skirt and the shirt
= 4 p - 1 p
= 3 p
= 3 x 20
= $60

Answer(s): $60