Warren had $271 and Japheth had $177 at first. Each of them bought an identical sweater and an identical skirt from the same shop. The skirt cost 4 times as much as the sweater. In the end, Warren had 3 times as much money as Japheth. What was the cost of the sweater?

	Warren	Japheth	Difference
Before	$271	$177	$94
Change	- 1 sweater - 1 skirt	- 1 sweater - 1 skirt
After	3 u	1 u	2 u

Since Warren and Japheth bought the same items, the difference  in their amounts remains the same.

Difference in the amounts that they had
= 3 u - 1 u
= 2 u

2 u = 271 - 177
2 u = 94

1 u = 94 ÷ 2 = 47

Amount that Japheth had in the end
= 1 u
= $47

Cost of 1 sweater and 1 skirt
= 177 - 1 u
= 177 - 47
= $130

The skirt cost 4 times as much as the sweater.

Cost of 1 sweater = 1 p
Cost of 1 skirt = 4 p

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

5 p = 130

1 p = 130 ÷ 5 = 26

Cost of the sweater
= 1 p
= $26

Answer(s): $26