Charlie and Oliver went shopping with a total amount of $384. They had $320 left after shopping. Charlie's remaining money was 3 times the amount he paid for. Oliver's remaining money was 7 times the amount he had spent.

1. How much did Oliver spend?
2. How much did Oliver bring along for shopping?

	Charlie	Oliver	Total
Before	4 u	8 p	384
Change	- 1 u	- 1 p	- 64
After	3 u	7 p	320

(a)
Amount that Charlie and Oliver spent
= 384 - 320
= $64

Amount that Charlie and Oliver spent
= 1 u + 1 p

1 u + 1 p = 64
1 u = 64 - 1 p --- (1)

Amount that Charlie and Oliver had left
= 3 u + 7 p 

3 u + 7 p = 320
3 u = 320 - 7 p --- (2)

Make u the same.

(1) _{x 3}
3 u = 192 - 3 p --- (3)

(3) = (2)
192 - 3 p = 320 - 7 p 
7 p - 3 p = 320 - 192

4 p = 128

1 p = 128 ÷ 4 = 32

Amount that Oliver spent = $32

(b)
Amount that Oliver brought along
= 8 p
= 8 x 32
= $256

Answer(s): (a) $32; (b) $256