Bobby and Glen went shopping with a total amount of $168. They had $144 left after shopping. Bobby's remaining money was 5 times the amount he paid for. Glen's remaining money was 7 times the amount he had spent.
- How much did Glen spend?
- How much did Glen bring along for shopping?
| |
Bobby |
Glen |
Total |
| Before |
6 u |
8 p |
168 |
| Change |
- 1 u |
- 1 p |
- 24 |
| After |
5 u |
7 p |
144 |
(a)
Amount that Bobby and Glen spent
= 168 - 144
= $24
Amount that Bobby and Glen spent
= 1 u + 1 p
1 u + 1 p = 24
1 u = 24 - 1 p --- (1)
Amount that Bobby and Glen had left
= 5 u + 7 p
5 u + 7 p = 144
5 u = 144 - 7 p --- (2)
Make u the same.
(1)
x 5 5 u = 120 - 5 p --- (3)
(3) = (2)
120 - 5 p = 144 - 7 p
7 p - 5 p = 144 - 120
2 p = 24
1 p = 24 ÷ 2 = 12
Amount that Glen spent = $12
(b)
Amount that Glen brought along
= 8 p
= 8 x 12
= $96
Answer(s): (a) $12; (b) $96
