PSLE At a sale, Peter bought 9 wine glasses of the same kind. His sister bought 7 such wine glasses. She also bought 3 glasses at $7.60 each. Altogether, she spent $6.60 more than Peter. What was the total amount of money Peter and his sister spent?
|
Peter |
His sister |
Items bought
|
9 wine glasses
|
7 wine glasses + 3 glasses = 7 wine glasses + 22.80 |
Comparing the amounts paid |
|
$6.60 more |
Amount that his sister spent on 3 glasses
= 3 x 7.60
= $22.80
Let the cost of 1 wine glass be 1 W.
If Peter's sister spent $6.60 less, each would pay the same amount.
9 W + 6.60 = 7 W + 22.80 - 6.60
9 W - 7 W = 22.80 - 6.60
2 W = 16.20
1 W = 16.20 ÷ 2 = 8.10
Total amount that Peter and his sister spent
= 9 W + 7 W + 22.80
= 16 W + 22.80
= 16 x 8.10 + 22.80
= 129.60 + 22.80
= $152.40
Answer(s): $152.40