PSLE A stationery shop is having a book sale.
The 1st book is at 10% discount.
The 2nd book is at 35% discount.
The price of the 2nd book should be equal or lower than the price of the 1st book.
Kathy and Warren each bought two books at the sale.
- Kathy's books were priced at $23 and $36. How much more did she pay for the 1st book than the 2nd book?
- Warren paid a total of $51.40 for his two books. He paid $9.80 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% $36 |
100% $23 |
|
Discount |
- 10% |
- 35% |
|
Sale price |
90% |
65% |
? |
(a)
Selling price of the 1st book
= 90% x 36
=
90100 x 36
= $32.40
Selling price of 2nd book
= 65% x 23
=
65100 x 23
= $14.95
Amount that Kathy paid more for the 1st book than the 2nd book
= 32.40 - 14.95
= $17.45
|
1st book |
2nd book |
Total amount |
Original price |
100% |
100% |
|
Discount |
- 10% |
- 35% |
|
Sale price |
90%
|
65%
|
|
Compare 1st book and 2nd book |
1 u + $9.80 |
1 u |
$51.40 |
(b)
Sale price of the 1st book = 1 u + 9.80
Sale price of the 2nd book = 1 u
Total amount that Warren paid
= 1 u + 9.80 + 1 u
= 2 u + 9.80
2 u + 9.80 = 51.40
2 u = 51.40 - 9.80
2 u = 41.60
1 u = 41.60 ÷ 2 = 20.80
Sale price of the 1st book
= 1 u + 9.80
= $30.60
90% of the price = $30.60
100% of the price =
30.6090 x 100 = $34
Selling price of the 1st book before discount = $34
Answer(s): (a) $17.45; (b) $34