PSLE
A stationery kiosk is having a book sale. The 1st book is at 5% discount. The 2nd book is at 20% discount. The price of the 2nd book should be equal or lower than the price of the 1st book.

1. Cathy's books were priced at $29 and $34. How much did she pay for them?
2. Gabriel paid a total of $46.75 for his two books. He paid $8.35 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% $34	100% $29
Discount	- 5%	- 20%
Sale price	95%	80%	?

(a)
Selling price of the 1st book
= 95% x 34
= ⁹⁵₁₀₀ x 34
= $32.30

Selling price of 2nd book
= 80% x 29
= ⁸⁰₁₀₀ x 29
= $23.20

Total amount that Cathy paid
= 32.30 + 23.20
= $55.50

	1st book	2nd book	Total amount
Original price	100%	100%
Discount	- 5%	- 20%
Sale price	95%	80%
Compare 1st book and 2nd book	1 u + $8.35	1 u	$46.75

(b)
Sale price of the 1st book = 1 u + 8.35
Sale price of the 2nd book = 1 u

Total amount that Gabriel paid
= 1 u + 8.35 + 1 u
= 2 u + 8.35

2 u + 8.35 = 46.75
2 u = 46.75 - 8.35
2 u = 38.40

1 u = 38.40 ÷ 2 = 19.20

Sale price of the 2nd book = $19.20

80% of the price = $19.20
100% of the price = ^19.20₈₀ x 100 = $24

Selling price of the 2nd book before discount = $24

Answer(s): (a) $55.50; (b) $24