PSLE A book shop is having a book sale.
The 1st book is at 5% 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.
Kylie and Dylan each bought two books at the sale.
- Kylie's books were priced at $21 and $21. How much more did she pay for the 1st book than the 2nd book?
- Dylan paid a total of $40.40 for his two books. He paid $5.20 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% $21 |
100% $21 |
|
Discount |
- 5% |
- 20% |
|
Sale price |
95% |
80% |
? |
(a)
Selling price of the 1st book
= 95% x 21
=
95100 x 21
= $19.95
Selling price of 2nd book
= 80% x 21
=
80100 x 21
= $16.80
Amount that Kylie paid more for the 1st book than the 2nd book
= 19.95 - 16.80
= $3.15
|
1st book |
2nd book |
Total amount |
Original price |
100% |
100% |
|
Discount |
- 5% |
- 20% |
|
Sale price |
95%
|
80%
|
|
Compare 1st book and 2nd book |
1 u + $5.20 |
1 u |
$40.40 |
(b)
Sale price of the 1st book = 1 u + 5.20
Sale price of the 2nd book = 1 u
Total amount that Dylan paid
= 1 u + 5.20 + 1 u
= 2 u + 5.20
2 u + 5.20 = 40.40
2 u = 40.40 - 5.20
2 u = 35.20
1 u = 35.20 ÷ 2 = 17.60
Sale price of the 1st book
= 1 u + 5.20
= $22.80
95% of the price = $22.80
100% of the price =
22.8095 x 100 = $24
Selling price of the 1st book before discount = $24
Answer(s): (a) $3.15; (b) $24