PSLE A bookstore 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.
- Sarah's books were priced at $24 and $34. How much less did she pay for the 2nd book than the 1st book?
- Bobby paid a total of $47.90 for his two books. He paid $11.50 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% $34 |
100% $24 |
|
Discount |
- 10% |
- 30% |
|
Sale price |
90% |
70% |
? |
(a)
Selling price of the 1st book
= 90% x 34
=
90100 x 34
= $30.60
Selling price of 2nd book
= 70% x 24
=
70100 x 24
= $16.80
Amount that Sarah paid less for the 2nd book than the 1st book
= 30.60 - 16.80
= $13.80
|
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 + $11.50 |
1 u |
$47.90 |
(b)
Sale price of the 1st book = 1 u + 11.50
Sale price of the 2nd book = 1 u
Total amount that Bobby paid
= 1 u + 11.50 + 1 u
= 2 u + 11.50
2 u + 11.50 = 47.90
2 u = 47.90 - 11.50
2 u = 36.40
1 u = 36.40 ÷ 2 = 18.20
Sale price of the 1st book
= 1 u + 11.50
= $29.70
90% of the price = $29.70
100% of the price =
29.7090 x 100 = $33
Selling price of the 1st book before discount = $33
Answer(s): (a) $13.80; (b) $33