Michael and Luis had $150 and $130 respectively. Each of them bought a hoodie and a sweater at the same price. The cost of the hoodie was 4 times as much as the sweater. In the end, Michael had 3 times as much money as Luis. What was the difference between the cost of the sweater and the hoodie?

	Michael	Luis	Difference
Before	$150	$130	$20
Change	- 5 p	- 5 p
After	3 u	1 u	2 u

Since Michael and Luis 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 = 150 - 130
2 u = 20

1 u = 20 ÷ 2 = 10

Cost of 1 hoodie = 4 p
Cost of 1 sweater = 1 p

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

5 p = 130 - 10
5 p = 120

1 p = 120 ÷ 5 = 24

Difference in the cost between the hoodie and the sweater
= 4 p - 1 p
= 3 p
= 3 x 24
= $72

Answer(s): $72