PSLE
A stationery kiosk is having a book sale. The 1st book is at 25% 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.

1. Abi's books were priced at $27 and $34. How much more did she pay for the 1st book than the 2nd book? 
2. Brandon paid a total of $43.65 for his two books. He paid $5.85 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% $34	100% $27
Discount	- 25%	- 30%
Sale price	75%	70%	?

(a)
Selling price of the 1st book
= 75% x 34
= ⁷⁵₁₀₀ x 34
= $25.50

Selling price of 2nd book
= 70% x 27
= ⁷⁰₁₀₀ x 27
= $18.90

Amount that Abi paid more for the 1st book than the 2nd book
= 25.50 - 18.90
= $6.60

	1st book	2nd book	Total amount
Original price	100%	100%
Discount	- 25%	- 30%
Sale price	75%	70%
Compare 1st book and 2nd book	1 u + $5.85	1 u	$43.65

(b)
Sale price of the 1st book = 1 u + 5.85
Sale price of the 2nd book = 1 u

Total amount that Brandon paid
= 1 u + 5.85 + 1 u
= 2 u + 5.85

2 u + 5.85 = 43.65
2 u = 43.65 - 5.85
2 u = 37.80

1 u = 37.80 ÷ 2 = 18.90

Sale price of the 1st book
= 1 u + 5.85
= $24.75

75% of the price = $24.75
100% of the price = ^24.75₇₅ x 100 = $33

Selling price of the 1st book before discount = $33

Answer(s): (a) $6.60; (b) $33