PSLE A shop is having a book sale.
The 1st book is at 5% discount.
The 2nd book is at 10% discount.
The price of the 2nd book should be equal or lower than the price of the 1st book.
Lucy and Reggie each bought two books at the sale.
- Lucy's books were priced at $15 and $21. How much did she pay for them?
- Reggie paid a total of $40.90 for his two books. He paid $8.50 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% $21 |
100% $15 |
|
Discount |
- 5% |
- 10% |
|
Sale price |
95% |
90% |
? |
(a)
Selling price of the 1st book
= 95% x 21
=
95100 x 21
= $19.95
Selling price of 2nd book
= 90% x 15
=
90100 x 15
= $13.50
Total amount that Lucy paid
= 19.95 + 13.50
= $33.45
|
1st book |
2nd book |
Total amount |
Original price |
100% |
100% |
|
Discount |
- 5% |
- 10% |
|
Sale price |
95%
|
90%
|
|
Compare 1st book and 2nd book |
1 u + $8.50 |
1 u |
$40.90 |
(b)
Sale price of the 1st book = 1 u + 8.50
Sale price of the 2nd book = 1 u
Total amount that Reggie paid
= 1 u + 8.50 + 1 u
= 2 u + 8.50
2 u + 8.50 = 40.90
2 u = 40.90 - 8.50
2 u = 32.40
1 u = 32.40 ÷ 2 = 16.20
Sale price of the 2nd book = $16.20
90% of the price = $16.20
100% of the price =
16.2090 x 100 = $18
Selling price of the 2nd book before discount = $18
Answer(s): (a) $33.45; (b) $18