Riordan and Bryan had $190 and $138 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, Riordan had 5 times as much money as Bryan. What was the difference between the cost of the shirt and the skirt?

	Riordan	Bryan	Difference
Before	$190	$138	$52
Change	- 5 p	- 5 p
After	5 u	1 u	4 u

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

5 u - 1 u = 190 - 138
4 u = 52

1 u = 52 ÷ 4 = 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 = 138 - 13
5 p = 125

1 p = 125 ÷ 5 = 25

Difference in the cost between the skirt and the shirt
= 4 p - 1 p
= 3 p
= 3 x 25
= $75

Answer(s): $75