PSLE A shop is having a book sale.
The 1st book is at 10% discount.
The 2nd book is at 25% discount.
The price of the 2nd book should be equal or lower than the price of the 1st book.
Kathy and Bobby each bought two books at the sale.
- Kathy's books were priced at $21 and $26. How much less did she pay for the 2nd book than the 1st book?
- Bobby paid a total of $51.45 for his two books. He paid $7.95 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% $26 |
100% $21 |
|
Discount |
- 10% |
- 25% |
|
Sale price |
90% |
75% |
? |
(a)
Selling price of the 1st book
= 90% x 26
=
90100 x 26
= $23.40
Selling price of 2nd book
= 75% x 21
=
75100 x 21
= $15.75
Amount that Kathy paid less for the 2nd book than the 1st book
= 23.40 - 15.75
= $7.65
|
1st book |
2nd book |
Total amount |
Original price |
100% |
100% |
|
Discount |
- 10% |
- 25% |
|
Sale price |
90%
|
75%
|
|
Compare 1st book and 2nd book |
1 u + $7.95 |
1 u |
$51.45 |
(b)
Sale price of the 1st book = 1 u + 7.95
Sale price of the 2nd book = 1 u
Total amount that Bobby paid
= 1 u + 7.95 + 1 u
= 2 u + 7.95
2 u + 7.95 = 51.45
2 u = 51.45 - 7.95
2 u = 43.50
1 u = 43.50 ÷ 2 = 21.75
Sale price of the 1st book
= 1 u + 7.95
= $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) $7.65; (b) $33