PSLE A 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.
Kylie and Tim each bought two books at the sale.
- Kylie's books were priced at $7 and $12. How much less did she pay for the 2nd book than the 1st book?
- Tim paid a total of $31.25 for his two books. He paid $6.55 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% $12 |
100% $7 |
|
Discount |
- 10% |
- 35% |
|
Sale price |
90% |
65% |
? |
(a)
Selling price of the 1st book
= 90% x 12
=
90100 x 12
= $10.80
Selling price of 2nd book
= 65% x 7
=
65100 x 7
= $4.55
Amount that Kylie paid less for the 2nd book than the 1st book
= 10.80 - 4.55
= $6.25
|
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 + $6.55 |
1 u |
$31.25 |
(b)
Sale price of the 1st book = 1 u + 6.55
Sale price of the 2nd book = 1 u
Total amount that Tim paid
= 1 u + 6.55 + 1 u
= 2 u + 6.55
2 u + 6.55 = 31.25
2 u = 31.25 - 6.55
2 u = 24.70
1 u = 24.70 ÷ 2 = 12.35
Sale price of the 1st book
= 1 u + 6.55
= $18.90
90% of the price = $18.90
100% of the price =
18.9090 x 100 = $21
Selling price of the 1st book before discount = $21
Answer(s): (a) $6.25; (b) $21