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.
Risa and Tom each bought two books at the sale.
- Risa's books were priced at $24 and $24. How much did she pay for them?
- Tom paid a total of $27.70 for his two books. He paid $10.10 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% $24 |
100% $24 |
|
Discount |
- 10% |
- 20% |
|
Sale price |
90% |
80% |
? |
(a)
Selling price of the 1st book
= 90% x 24
=
90100 x 24
= $21.60
Selling price of 2nd book
= 80% x 24
=
80100 x 24
= $19.20
Total amount that Risa paid
= 21.60 + 19.20
= $40.80
|
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 + $10.10 |
1 u |
$27.70 |
(b)
Sale price of the 1st book = 1 u + 10.10
Sale price of the 2nd book = 1 u
Total amount that Tom paid
= 1 u + 10.10 + 1 u
= 2 u + 10.10
2 u + 10.10 = 27.70
2 u = 27.70 - 10.10
2 u = 17.60
1 u = 17.60 ÷ 2 = 8.80
Sale price of the 2nd book = $8.80
80% of the price = $8.80
100% of the price =
8.8080 x 100 = $11
Selling price of the 2nd book before discount = $11
Answer(s): (a) $40.80; (b) $11