Ken had $332 and Zane had $173 at first. Each of them bought an identical cardigan and an identical windbreaker from the same shop. The windbreaker cost 2 times as much as the cardigan. In the end, Ken had 4 times as much money as Zane. What was the cost of the cardigan?

	Ken	Zane	Difference
Before	$332	$173	$159
Change	- 1 cardigan - 1 windbreaker	- 1 cardigan - 1 windbreaker
After	4 u	1 u	3 u

Since Ken and Zane bought the same items, the difference  in their amounts remains the same.

Difference in the amounts that they had
= 4 u - 1 u
= 3 u

3 u = 332 - 173
3 u = 159

1 u = 159 ÷ 3 = 53

Amount that Zane had in the end
= 1 u
= $53

Cost of 1 cardigan and 1 windbreaker
= 173 - 1 u
= 173 - 53
= $120

The windbreaker cost 2 times as much as the cardigan.

Cost of 1 cardigan = 1 p
Cost of 1 windbreaker = 2 p

Total cost of 1 cardigan and 1 windbreaker
= 1 p + 2 p
= 3 p

3 p = 120

1 p = 120 ÷ 3 = 40

Cost of the cardigan
= 1 p
= $40

Answer(s): $40