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.
- Opal's books were priced at $4 and $15. How much less did she pay for the 2nd book than the 1st book?
- Ivan paid a total of $45.70 for his two books. He paid $11.90 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% $15 |
100% $4 |
|
Discount |
- 10% |
- 35% |
|
Sale price |
90% |
65% |
? |
(a)
Selling price of the 1st book
= 90% x 15
=
90100 x 15
= $13.50
Selling price of 2nd book
= 65% x 4
=
65100 x 4
= $2.60
Amount that Opal paid less for the 2nd book than the 1st book
= 13.50 - 2.60
= $10.90
|
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 + $11.90 |
1 u |
$45.70 |
(b)
Sale price of the 1st book = 1 u + 11.90
Sale price of the 2nd book = 1 u
Total amount that Ivan paid
= 1 u + 11.90 + 1 u
= 2 u + 11.90
2 u + 11.90 = 45.70
2 u = 45.70 - 11.90
2 u = 33.80
1 u = 33.80 ÷ 2 = 16.90
Sale price of the 1st book
= 1 u + 11.90
= $28.80
90% of the price = $28.80
100% of the price =
28.8090 x 100 = $32
Selling price of the 1st book before discount = $32
Answer(s): (a) $10.90; (b) $32