PSLE A 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 Sam each bought two books at the sale.
- Abi's books were priced at $21 and $26. How much less did she pay for the 2nd book than the 1st book?
- Sam paid a total of $35.10 for his two books. He paid $9.90 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% $26 |
100% $21 |
|
Discount |
- 10% |
- 30% |
|
Sale price |
90% |
70% |
? |
(a)
Selling price of the 1st book
= 90% x 26
=
90100 x 26
= $23.40
Selling price of 2nd book
= 70% x 21
=
70100 x 21
= $14.70
Amount that Abi paid less for the 2nd book than the 1st book
= 23.40 - 14.70
= $8.70
|
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 + $9.90 |
1 u |
$35.10 |
(b)
Sale price of the 1st book = 1 u + 9.90
Sale price of the 2nd book = 1 u
Total amount that Sam paid
= 1 u + 9.90 + 1 u
= 2 u + 9.90
2 u + 9.90 = 35.10
2 u = 35.10 - 9.90
2 u = 25.20
1 u = 25.20 ÷ 2 = 12.60
Sale price of the 1st book
= 1 u + 9.90
= $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) $8.70; (b) $25