PSLE A store is having a book sale.
The 1st book is at 5% 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.
Usha and Sam each bought two books at the sale.
- Usha's books were priced at $18 and $19. How much less did she pay for the 2nd book than the 1st book?
- Sam paid a total of $35.40 for his two books. He paid $10.20 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% $19 |
100% $18 |
|
Discount |
- 5% |
- 30% |
|
Sale price |
95% |
70% |
? |
(a)
Selling price of the 1st book
= 95% x 19
=
95100 x 19
= $18.05
Selling price of 2nd book
= 70% x 18
=
70100 x 18
= $12.60
Amount that Usha paid less for the 2nd book than the 1st book
= 18.05 - 12.60
= $5.45
|
1st book |
2nd book |
Total amount |
Original price |
100% |
100% |
|
Discount |
- 5% |
- 30% |
|
Sale price |
95%
|
70%
|
|
Compare 1st book and 2nd book |
1 u + $10.20 |
1 u |
$35.40 |
(b)
Sale price of the 1st book = 1 u + 10.20
Sale price of the 2nd book = 1 u
Total amount that Sam paid
= 1 u + 10.20 + 1 u
= 2 u + 10.20
2 u + 10.20 = 35.40
2 u = 35.40 - 10.20
2 u = 25.20
1 u = 25.20 ÷ 2 = 12.60
Sale price of the 1st book
= 1 u + 10.20
= $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) $5.45; (b) $24