PSLE
A shop is having a book sale. The 1st book is at 15% 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. Fiona's books were priced at $1 and $14. How much did she pay for them?
2. Carl paid a total of $27.65 for his two books. He paid $8.05 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% $14	100% $1
Discount	- 15%	- 30%
Sale price	85%	70%	?

(a)
Selling price of the 1st book
= 85% x 14
= ⁸⁵₁₀₀ x 14
= $11.90

Selling price of 2nd book
= 70% x 1
= ⁷⁰₁₀₀ x 1
= $0.70

Total amount that Fiona paid
= 11.90 + 0.70
= $12.60

	1st book	2nd book	Total amount
Original price	100%	100%
Discount	- 15%	- 30%
Sale price	85%	70%
Compare 1st book and 2nd book	1 u + $8.05	1 u	$27.65

(b)
Sale price of the 1st book = 1 u + 8.05
Sale price of the 2nd book = 1 u

Total amount that Carl paid
= 1 u + 8.05 + 1 u
= 2 u + 8.05

2 u + 8.05 = 27.65
2 u = 27.65 - 8.05
2 u = 19.60

1 u = 19.60 ÷ 2 = 9.80

Sale price of the 2nd book = $9.80

70% of the price = $9.80
100% of the price = ^9.80₇₀ x 100 = $14

Selling price of the 2nd book before discount = $14

Answer(s): (a) $12.60; (b) $14