Warren and Archie went shopping with a total amount of $130. They had $110 left after shopping. Warren's remaining money was 4 times the amount he paid for. Archie's remaining money was 7 times the amount he had spent.

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

	Warren	Archie	Total
Before	5 u	8 p	130
Change	- 1 u	- 1 p	- 20
After	4 u	7 p	110

(a)
Amount that Warren and Archie spent
= 130 - 110
= $20

Amount that Warren and Archie spent
= 1 u + 1 p

1 u + 1 p = 20
1 u = 20 - 1 p --- (1)

Amount that Warren and Archie had left
= 4 u + 7 p 

4 u + 7 p = 110
4 u = 110 - 7 p --- (2)

Make u the same.

(1) _{x 4}
4 u = 80 - 4 p --- (3)

(3) = (2)
80 - 4 p = 110 - 7 p 
7 p - 4 p = 110 - 80

3 p = 30

1 p = 30 ÷ 3 = 10

Amount that Archie spent = $10

(b)
Amount that Archie brought along
= 8 p
= 8 x 10
= $80

Answer(s): (a) $10; (b) $80