Michael and Julian had $180 and $120 respectively. Each of them bought a sweater and a cardigan at the same price. The cost of the sweater was 4 times as much as the cardigan. In the end, Michael had 5 times as much money as Julian. What was the difference between the cost of the cardigan and the sweater?

	Michael	Julian	Difference
Before	$180	$120	$60
Change	- 5 p	- 5 p
After	5 u	1 u	4 u

Since Michael and Julian 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 = 180 - 120
4 u = 60

1 u = 60 ÷ 4 = 15

Cost of 1 sweater = 4 p
Cost of 1 cardigan = 1 p

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

5 p = 120 - 15
5 p = 105

1 p = 105 ÷ 5 = 21

Difference in the cost between the sweater and the cardigan
= 4 p - 1 p
= 3 p
= 3 x 21
= $63

Answer(s): $63