PSLE A shop is having a book sale. The 1st book is at 10% discount. The 2nd book is at 40% discount. The price of the 2nd book should be equal or lower than the price of the 1st book.
- Yoko's books were priced at $21 and $33. How much less did she pay for the 2nd book than the 1st book?
- Flynn paid a total of $56.70 for his two books. He paid $13.50 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% $33 |
100% $21 |
|
Discount |
- 10% |
- 40% |
|
Sale price |
90% |
60% |
? |
(a)
Selling price of the 1st book
= 90% x 33
=
90100 x 33
= $29.70
Selling price of 2nd book
= 60% x 21
=
60100 x 21
= $12.60
Amount that Yoko paid less for the 2nd book than the 1st book
= 29.70 - 12.60
= $17.10
|
1st book |
2nd book |
Total amount |
Original price |
100% |
100% |
|
Discount |
- 10% |
- 40% |
|
Sale price |
90%
|
60%
|
|
Compare 1st book and 2nd book |
1 u + $13.50 |
1 u |
$56.70 |
(b)
Sale price of the 1st book = 1 u + 13.50
Sale price of the 2nd book = 1 u
Total amount that Flynn paid
= 1 u + 13.50 + 1 u
= 2 u + 13.50
2 u + 13.50 = 56.70
2 u = 56.70 - 13.50
2 u = 43.20
1 u = 43.20 ÷ 2 = 21.60
Sale price of the 1st book
= 1 u + 13.50
= $35.10
90% of the price = $35.10
100% of the price =
35.1090 x 100 = $39
Selling price of the 1st book before discount = $39
Answer(s): (a) $17.10; (b) $39