Dylan and Riordan went shopping with a total amount of $234. They had $198 left after shopping. Dylan's remaining money was 4 times the amount he paid for. Riordan's remaining money was 7 times the amount he had spent.

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

	Dylan	Riordan	Total
Before	5 u	8 p	234
Change	- 1 u	- 1 p	- 36
After	4 u	7 p	198

(a)
Amount that Dylan and Riordan spent
= 234 - 198
= $36

Amount that Dylan and Riordan spent
= 1 u + 1 p

1 u + 1 p = 36
1 u = 36 - 1 p --- (1)

Amount that Dylan and Riordan had left
= 4 u + 7 p 

4 u + 7 p = 198
4 u = 198 - 7 p --- (2)

Make u the same.

(1) _{x 4}
4 u = 144 - 4 p --- (3)

(3) = (2)
144 - 4 p = 198 - 7 p 
7 p - 4 p = 198 - 144

3 p = 54

1 p = 54 ÷ 3 = 18

Amount that Riordan spent = $18

(b)
Amount that Riordan brought along
= 8 p
= 8 x 18
= $144

Answer(s): (a) $18; (b) $144