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.
- Pamela's books were priced at $28 and $38. How much more did she pay for the 1st book than the 2nd book?
- Neave paid a total of $36.90 for his two books. He paid $11.70 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% $38 |
100% $28 |
|
Discount |
- 10% |
- 30% |
|
Sale price |
90% |
70% |
? |
(a)
Selling price of the 1st book
= 90% x 38
=
90100 x 38
= $34.20
Selling price of 2nd book
= 70% x 28
=
70100 x 28
= $19.60
Amount that Pamela paid more for the 1st book than the 2nd book
= 34.20 - 19.60
= $14.60
|
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 + $11.70 |
1 u |
$36.90 |
(b)
Sale price of the 1st book = 1 u + 11.70
Sale price of the 2nd book = 1 u
Total amount that Neave paid
= 1 u + 11.70 + 1 u
= 2 u + 11.70
2 u + 11.70 = 36.90
2 u = 36.90 - 11.70
2 u = 25.20
1 u = 25.20 ÷ 2 = 12.60
Sale price of the 1st book
= 1 u + 11.70
= $24.30
90% of the price = $24.30
100% of the price =
24.3090 x 100 = $27
Selling price of the 1st book before discount = $27
Answer(s): (a) $14.60; (b) $27