PSLE A stationery shop is having a book sale. The 1st book is at 10% discount. The 2nd book is at 20% discount. The price of the 2nd book should be equal or lower than the price of the 1st book.
- Jane's books were priced at $9 and $21. How much did she pay for them?
- Tim paid a total of $50.30 for his two books. He paid $5.50 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% $9 |
|
Discount |
- 10% |
- 20% |
|
Sale price |
90% |
80% |
? |
(a)
Selling price of the 1st book
= 90% x 21
=
90100 x 21
= $18.90
Selling price of 2nd book
= 80% x 9
=
80100 x 9
= $7.20
Total amount that Jane paid
= 18.90 + 7.20
= $26.10
|
1st book |
2nd book |
Total amount |
Original price |
100% |
100% |
|
Discount |
- 10% |
- 20% |
|
Sale price |
90%
|
80%
|
|
Compare 1st book and 2nd book |
1 u + $5.50 |
1 u |
$50.30 |
(b)
Sale price of the 1st book = 1 u + 5.50
Sale price of the 2nd book = 1 u
Total amount that Tim paid
= 1 u + 5.50 + 1 u
= 2 u + 5.50
2 u + 5.50 = 50.30
2 u = 50.30 - 5.50
2 u = 44.80
1 u = 44.80 ÷ 2 = 22.40
Sale price of the 2nd book = $22.40
80% of the price = $22.40
100% of the price =
22.4080 x 100 = $28
Selling price of the 2nd book before discount = $28
Answer(s): (a) $26.10; (b) $28