PSLE A stationery shop is having a book sale.
The 1st book is at 10% discount.
The 2nd book is at 30% discount.
The price of the 2nd book should be equal or lower than the price of the 1st book.
Abi and George each bought two books at the sale.
- Abi's books were priced at $3 and $17. How much less did she pay for the 2nd book than the 1st book?
- George paid a total of $51.10 for his two books. He paid $11.90 less for the 2nd book than for the 1st book. What was the price of the 1st book before discount?
|
1st book |
2nd book |
Total amount |
Original price
|
100% $17 |
100% $3 |
|
Discount |
- 10% |
- 30% |
|
Sale price |
90% |
70% |
? |
(a)
Selling price of the 1st book
= 90% x 17
=
90100 x 17
= $15.30
Selling price of 2nd book
= 70% x 3
=
70100 x 3
= $2.10
Amount that Abi paid less for the 2nd book than the 1st book
= 15.30 - 2.10
= $13.20
|
1st book |
2nd book |
Total amount |
Original price |
100% |
100% |
|
Discount |
- 10% |
- 30% |
|
Sale price |
90%
|
70%
|
|
Compare 1st book and 2nd book |
1 u + $11.90 |
1 u |
$51.10 |
(b)
Sale price of the 1st book = 1 u + 11.90
Sale price of the 2nd book = 1 u
Total amount that George paid
= 1 u + 11.90 + 1 u
= 2 u + 11.90
2 u + 11.90 = 51.10
2 u = 51.10 - 11.90
2 u = 39.20
1 u = 39.20 ÷ 2 = 19.60
Sale price of the 1st book
= 1 u + 11.90
= $31.50
90% of the price = $31.50
100% of the price =
31.5090 x 100 = $35
Selling price of the 1st book before discount = $35
Answer(s): (a) $13.20; (b) $35