PSLE A book 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.
Nora and Brandon each bought two books at the sale.
- Nora's books were priced at $7 and $17. How much less did she pay for the 2nd book than the 1st book?
- Brandon paid a total of $28.25 for his two books. He paid $9.55 more for the 1st book than for the 2nd book. What was the price of the 1st book before discount?
|
1st book |
2nd book |
Total amount |
Original price
|
100% $17 |
100% $7 |
|
Discount |
- 10% |
- 15% |
|
Sale price |
90% |
85% |
? |
(a)
Selling price of the 1st book
= 90% x 17
=
90100 x 17
= $15.30
Selling price of 2nd book
= 85% x 7
=
85100 x 7
= $5.95
Amount that Nora paid less for the 2nd book than the 1st book
= 15.30 - 5.95
= $9.35
|
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 + $9.55 |
1 u |
$28.25 |
(b)
Sale price of the 1st book = 1 u + 9.55
Sale price of the 2nd book = 1 u
Total amount that Brandon paid
= 1 u + 9.55 + 1 u
= 2 u + 9.55
2 u + 9.55 = 28.25
2 u = 28.25 - 9.55
2 u = 18.70
1 u = 18.70 ÷ 2 = 9.35
Sale price of the 1st book
= 1 u + 9.55
= $18.90
90% of the price = $18.90
100% of the price =
18.9090 x 100 = $21
Selling price of the 1st book before discount = $21
Answer(s): (a) $9.35; (b) $21