PSLE A shop is having a book sale. The 1st book is at 15% discount. The 2nd book is at 20% discount. The price of the 2nd book should be equal or lower than the price of the 1st book.
- Cindy's books were priced at $13 and $28. How much more did she pay for the 1st book than the 2nd book?
- Peter paid a total of $47.95 for his two books. He paid $4.75 less for the 2nd book than for the 1st book. What was the price of the 1st book before discount?
|
1st book |
2nd book |
Total amount |
Original price
|
100% $28 |
100% $13 |
|
Discount |
- 15% |
- 20% |
|
Sale price |
85% |
80% |
? |
(a)
Selling price of the 1st book
= 85% x 28
=
85100 x 28
= $23.80
Selling price of 2nd book
= 80% x 13
=
80100 x 13
= $10.40
Amount that Cindy paid more for the 1st book than the 2nd book
= 23.80 - 10.40
= $13.40
|
1st book |
2nd book |
Total amount |
Original price |
100% |
100% |
|
Discount |
- 15% |
- 20% |
|
Sale price |
85%
|
80%
|
|
Compare 1st book and 2nd book |
1 u + $4.75 |
1 u |
$47.95 |
(b)
Sale price of the 1st book = 1 u + 4.75
Sale price of the 2nd book = 1 u
Total amount that Peter paid
= 1 u + 4.75 + 1 u
= 2 u + 4.75
2 u + 4.75 = 47.95
2 u = 47.95 - 4.75
2 u = 43.20
1 u = 43.20 ÷ 2 = 21.60
Sale price of the 1st book
= 1 u + 4.75
= $26.35
85% of the price = $26.35
100% of the price =
26.3585 x 100 = $31
Selling price of the 1st book before discount = $31
Answer(s): (a) $13.40; (b) $31