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.
Ivory and Cole each bought two books at the sale.
- Ivory's books were priced at $13 and $15. How much more did she pay for the 1st book than the 2nd book?
- Cole paid a total of $35.30 for his two books. He paid $11.50 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% $15 |
100% $13 |
|
Discount |
- 10% |
- 30% |
|
Sale price |
90% |
70% |
? |
(a)
Selling price of the 1st book
= 90% x 15
=
90100 x 15
= $13.50
Selling price of 2nd book
= 70% x 13
=
70100 x 13
= $9.10
Amount that Ivory paid more for the 1st book than the 2nd book
= 13.50 - 9.10
= $4.40
|
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 + $11.50 |
1 u |
$35.30 |
(b)
Sale price of the 1st book = 1 u + 11.50
Sale price of the 2nd book = 1 u
Total amount that Cole paid
= 1 u + 11.50 + 1 u
= 2 u + 11.50
2 u + 11.50 = 35.30
2 u = 35.30 - 11.50
2 u = 23.80
1 u = 23.80 ÷ 2 = 11.90
Sale price of the 1st book
= 1 u + 11.50
= $23.40
90% of the price = $23.40
100% of the price =
23.4090 x 100 = $26
Selling price of the 1st book before discount = $26
Answer(s): (a) $4.40; (b) $26