Peter and Ethan had $168 and $136 respectively. Each of them bought a skirt and a cardigan at the same price. The cost of the skirt was 5 times as much as the cardigan. In the end, Peter had 3 times as much money as Ethan. What was the difference between the cost of the cardigan and the skirt?

	Peter	Ethan	Difference
Before	$168	$136	$32
Change	- 6 p	- 6 p
After	3 u	1 u	2 u

Since Peter and Ethan 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 = 168 - 136
2 u = 32

1 u = 32 ÷ 2 = 16

Cost of 1 skirt = 5 p
Cost of 1 cardigan = 1 p

Total cost of 1 skirt and 1 cardigan
= 5 p + 1 p
= 6 p

6 p = 136 - 16
6 p = 120

1 p = 120 ÷ 6 = 20

Difference in the cost between the skirt and the cardigan
= 5 p - 1 p
= 4 p
= 4 x 20
= $80

Answer(s): $80