PSLE A book 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.
Lucy and Oliver each bought two books at the sale.
- Lucy's books were priced at $22 and $35. How much less did she pay for the 2nd book than the 1st book?
- Oliver paid a total of $44.30 for his two books. He paid $7.90 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% $35 |
100% $22 |
|
Discount |
- 10% |
- 30% |
|
Sale price |
90% |
70% |
? |
(a)
Selling price of the 1st book
= 90% x 35
=
90100 x 35
= $31.50
Selling price of 2nd book
= 70% x 22
=
70100 x 22
= $15.40
Amount that Lucy paid less for the 2nd book than the 1st book
= 31.50 - 15.40
= $16.10
|
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 + $7.90 |
1 u |
$44.30 |
(b)
Sale price of the 1st book = 1 u + 7.90
Sale price of the 2nd book = 1 u
Total amount that Oliver paid
= 1 u + 7.90 + 1 u
= 2 u + 7.90
2 u + 7.90 = 44.30
2 u = 44.30 - 7.90
2 u = 36.40
1 u = 36.40 ÷ 2 = 18.20
Sale price of the 1st book
= 1 u + 7.90
= $26.10
90% of the price = $26.10
100% of the price =
26.1090 x 100 = $29
Selling price of the 1st book before discount = $29
Answer(s): (a) $16.10; (b) $29