Pierre bought some pastries. He bought some wafers with $6.50 more than half his money. He then bought some biscuits with $7.80 less than half of his remaining money. He then had $12.90 left. How much did he pay for the wafers?
| Wafers |
Remaining amount |
| 1 u + $6.50 |
1 u - $6.50 |
| |
Biscuits |
Left |
| |
1 p - $7.80 |
1 p + $7.80 |
| |
|
$12.90 |
Working backwards.
Amount that Pierre had left = 1 p + 7.80
1 p + 7.80 = 12.90
1 p = 12.90 - 7.80 = 5.10
Remaining amount after he bought some wafers
= 2 p
= 2 x 5.10
= $10.20
Remaining amount after he bought some wafers = 1 u - 6.50
1 u - 6.50 = 10.20
1 u = 10.20 + 6.50
1 u = 16.70
Amount that Pierre spent on some wafers
= 1 u + 6.50
= 16.70 + 6.50
= $23.20
Answer(s): $23.20
