Oscar and John had $145 and $105 respectively. Each of them bought a jacket and a shirt at the same price. The cost of the jacket was 4 times as much as the shirt. In the end, Oscar had 5 times as much money as John. What was the difference between the cost of the shirt and the jacket?

	Oscar	John	Difference
Before	$145	$105	$40
Change	- 5 p	- 5 p
After	5 u	1 u	4 u

Since Oscar and John 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 = 145 - 105
4 u = 40

1 u = 40 ÷ 4 = 10

Cost of 1 jacket = 4 p
Cost of 1 shirt = 1 p

Total cost of 1 jacket and 1 shirt
= 4 p + 1 p
= 5 p

5 p = 105 - 10
5 p = 95

1 p = 95 ÷ 5 = 19

Difference in the cost between the jacket and the shirt
= 4 p - 1 p
= 3 p
= 3 x 19
= $57

Answer(s): $57