PSLE A shop is having a book sale. The 1st book is at 5% discount. The 2nd book is at 10% discount. The price of the 2nd book should be equal or lower than the price of the 1st book.
- Anna's books were priced at $17 and $22. How much more did she pay for the 1st book than the 2nd book?
- Sam paid a total of $38.95 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% $22 |
100% $17 |
|
Discount |
- 5% |
- 10% |
|
Sale price |
95% |
90% |
? |
(a)
Selling price of the 1st book
= 95% x 22
=
95100 x 22
= $20.90
Selling price of 2nd book
= 90% x 17
=
90100 x 17
= $15.30
Amount that Anna paid more for the 1st book than the 2nd book
= 20.90 - 15.30
= $5.60
|
1st book |
2nd book |
Total amount |
Original price |
100% |
100% |
|
Discount |
- 5% |
- 10% |
|
Sale price |
95%
|
90%
|
|
Compare 1st book and 2nd book |
1 u + $4.75 |
1 u |
$38.95 |
(b)
Sale price of the 1st book = 1 u + 4.75
Sale price of the 2nd book = 1 u
Total amount that Sam paid
= 1 u + 4.75 + 1 u
= 2 u + 4.75
2 u + 4.75 = 38.95
2 u = 38.95 - 4.75
2 u = 34.20
1 u = 34.20 ÷ 2 = 17.10
Sale price of the 1st book
= 1 u + 4.75
= $21.85
95% of the price = $21.85
100% of the price =
21.8595 x 100 = $23
Selling price of the 1st book before discount = $23
Answer(s): (a) $5.60; (b) $23