Luis and Pierre went shopping with a total amount of $154. They had $126 left after shopping. Luis's remaining money was 3 times the amount he paid for. Pierre's remaining money was 6 times the amount he had spent.
- How much did Pierre spend?
- How much did Pierre bring along for shopping?
| |
Luis |
Pierre |
Total |
| Before |
4 u |
7 p |
154 |
| Change |
- 1 u |
- 1 p |
- 28 |
| After |
3 u |
6 p |
126 |
(a)
Amount that Luis and Pierre spent
= 154 - 126
= $28
Amount that Luis and Pierre spent
= 1 u + 1 p
1 u + 1 p = 28
1 u = 28 - 1 p --- (1)
Amount that Luis and Pierre had left
= 3 u + 6 p
3 u + 6 p = 126
3 u = 126 - 6 p --- (2)
Make u the same.
(1)
x 3 3 u = 84 - 3 p --- (3)
(3) = (2)
84 - 3 p = 126 - 6 p
6 p - 3 p = 126 - 84
3 p = 42
1 p = 42 ÷ 3 = 14
Amount that Pierre spent = $14
(b)
Amount that Pierre brought along
= 7 p
= 7 x 14
= $98
Answer(s): (a) $14; (b) $98
