PSLE A book shop is having a book sale.
The 1st book is at 10% discount.
The 2nd book is at 40% discount.
The price of the 2nd book should be equal or lower than the price of the 1st book.
Roshel and Julian each bought two books at the sale.
- Roshel's books were priced at $21 and $35. How much more did she pay for the 1st book than the 2nd book?
- Julian paid a total of $33.30 for his two books. He paid $11.70 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% $35 |
100% $21 |
|
Discount |
- 10% |
- 40% |
|
Sale price |
90% |
60% |
? |
(a)
Selling price of the 1st book
= 90% x 35
=
90100 x 35
= $31.50
Selling price of 2nd book
= 60% x 21
=
60100 x 21
= $12.60
Amount that Roshel paid more for the 1st book than the 2nd book
= 31.50 - 12.60
= $18.90
|
1st book |
2nd book |
Total amount |
Original price |
100% |
100% |
|
Discount |
- 10% |
- 40% |
|
Sale price |
90%
|
60%
|
|
Compare 1st book and 2nd book |
1 u + $11.70 |
1 u |
$33.30 |
(b)
Sale price of the 1st book = 1 u + 11.70
Sale price of the 2nd book = 1 u
Total amount that Julian paid
= 1 u + 11.70 + 1 u
= 2 u + 11.70
2 u + 11.70 = 33.30
2 u = 33.30 - 11.70
2 u = 21.60
1 u = 21.60 ÷ 2 = 10.80
Sale price of the 1st book
= 1 u + 11.70
= $22.50
90% of the price = $22.50
100% of the price =
22.5090 x 100 = $25
Selling price of the 1st book before discount = $25
Answer(s): (a) $18.90; (b) $25