PSLE A shop is having a book sale.
The 1st book is at 10% discount.
The 2nd book is at 15% discount.
The price of the 2nd book should be equal or lower than the price of the 1st book.
Irene and Billy each bought two books at the sale.
- Irene's books were priced at $3 and $11. How much did she pay for them?
- Billy paid a total of $33.35 for his two books. He paid $4.45 less for the 2nd book than the 1st book. What was the price of the 2nd book before discount?
|
1st book |
2nd book |
Total amount |
Original price
|
100% $11 |
100% $3 |
|
Discount |
- 10% |
- 15% |
|
Sale price |
90% |
85% |
? |
(a)
Selling price of the 1st book
= 90% x 11
=
90100 x 11
= $9.90
Selling price of 2nd book
= 85% x 3
=
85100 x 3
= $2.55
Total amount that Irene paid
= 9.90 + 2.55
= $12.45
|
1st book |
2nd book |
Total amount |
Original price |
100% |
100% |
|
Discount |
- 10% |
- 15% |
|
Sale price |
90%
|
85%
|
|
Compare 1st book and 2nd book |
1 u + $4.45 |
1 u |
$33.35 |
(b)
Sale price of the 1st book = 1 u + 4.45
Sale price of the 2nd book = 1 u
Total amount that Billy paid
= 1 u + 4.45 + 1 u
= 2 u + 4.45
2 u + 4.45 = 33.35
2 u = 33.35 - 4.45
2 u = 28.90
1 u = 28.90 ÷ 2 = 14.45
Sale price of the 2nd book = $14.45
85% of the price = $14.45
100% of the price =
14.4585 x 100 = $17
Selling price of the 2nd book before discount = $17
Answer(s): (a) $12.45; (b) $17