Charlie and Jack went shopping with a total amount of $144. They had $120 left after shopping. Charlie's remaining money was 4 times the amount he paid for. Jack's remaining money was 6 times the amount he had spent.
- How much did Jack spend?
- How much did Jack bring along for shopping?
| |
Charlie |
Jack |
Total |
| Before |
5 u |
7 p |
144 |
| Change |
- 1 u |
- 1 p |
- 24 |
| After |
4 u |
6 p |
120 |
(a)
Amount that Charlie and Jack spent
= 144 - 120
= $24
Amount that Charlie and Jack spent
= 1 u + 1 p
1 u + 1 p = 24
1 u = 24 - 1 p --- (1)
Amount that Charlie and Jack had left
= 4 u + 6 p
4 u + 6 p = 120
4 u = 120 - 6 p --- (2)
Make u the same.
(1)
x 4 4 u = 96 - 4 p --- (3)
(3) = (2)
96 - 4 p = 120 - 6 p
6 p - 4 p = 120 - 96
2 p = 24
1 p = 24 ÷ 2 = 12
Amount that Jack spent = $12
(b)
Amount that Jack brought along
= 7 p
= 7 x 12
= $84
Answer(s): (a) $12; (b) $84
