PSLE
A store is having a book sale. The 1st book is at 15% discount. The 2nd book is at 40% discount. The price of the 2nd book should be equal or lower than the price of the 1st book.

1. Usha's books were priced at $34 and $37. How much did she pay for them?
2. Cole paid a total of $38.95 for his two books. He paid $13.75 more for the 1st book than the 2nd book. What was the price of the 2nd book before discount? 

	1st book	2nd book	Total amount
Original price	100% $37	100% $34
Discount	- 15%	- 40%
Sale price	85%	60%	?

(a)
Selling price of the 1st book
= 85% x 37
= ⁸⁵₁₀₀ x 37
= $31.45

Selling price of 2nd book
= 60% x 34
= ⁶⁰₁₀₀ x 34
= $20.40

Total amount that Usha paid
= 31.45 + 20.40
= $51.85

	1st book	2nd book	Total amount
Original price	100%	100%
Discount	- 15%	- 40%
Sale price	85%	60%
Compare 1st book and 2nd book	1 u + $13.75	1 u	$38.95

(b)
Sale price of the 1st book = 1 u + 13.75
Sale price of the 2nd book = 1 u

Total amount that Cole paid
= 1 u + 13.75 + 1 u
= 2 u + 13.75

2 u + 13.75 = 38.95
2 u = 38.95 - 13.75
2 u = 25.20

1 u = 25.20 ÷ 2 = 12.60

Sale price of the 2nd book = $12.60

60% of the price = $12.60
100% of the price = ^12.60₆₀ x 100 = $21

Selling price of the 2nd book before discount = $21

Answer(s): (a) $51.85; (b) $21