Caden and Neave had $80 and $70 respectively. Each of them bought a jacket and a cardigan at the same price. The cost of the jacket was 4 times as much as the cardigan. In the end, Caden had 3 times as much money as Neave. What was the difference between the cost of the cardigan and the jacket?

	Caden	Neave	Difference
Before	$80	$70	$10
Change	- 5 p	- 5 p
After	3 u	1 u	2 u

Since Caden and Neave 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 = 80 - 70
2 u = 10

1 u = 10 ÷ 2 = 5

Cost of 1 jacket = 4 p
Cost of 1 cardigan = 1 p

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

5 p = 70 - 5
5 p = 65

1 p = 65 ÷ 5 = 13

Difference in the cost between the jacket and the cardigan
= 4 p - 1 p
= 3 p
= 3 x 13
= $39

Answer(s): $39