A book store had 640 fiction books. There were Malay, Chinese and English fiction books in the ratio of 3 : 8 : 5. When the book store assistant brought in another 184 new fiction books, the number of Malay fiction books was increased by 20% and the number of Chinese fiction books was increased by ³₈.

1. What was the number of English fiction books that the book store assistant brought in?
2. What was the percentage increase in the number of English fiction books?

	Malay	Chinese	English	Total
Before	3 u	8 u	5 u	640
Change	+ 0.6 u	+ 3 u	+ ?	+ 184
After	3.6 u	11 u	6 u	824

Increase in the number of Malay fiction books
= 20% x 3 u
= ²⁰₁₀₀ x 3 u
= 0.6 u

Increase in the number of Chinese fiction books
= ³₈ x 8 u
= 3 u

Total number of fiction books at first
= 3 u + 8 u + 5 u
= 16 u

16 u = 640

1 u = 640 ÷ 16 = 40

Increase in the number of Malay and Chinese fiction books
= 0.6 u + 3 u
= 3.6 u
= 3.6 x 40
= 144

Number of English fiction books brought in
= 184 - 144
= 40 

(b)
Number of English fiction books at first
= 5 u
= 5 x 40
= 200

Percentage increase in English fiction books
= ⁴⁰₂₀₀ x 100%
= 20%

Answer(s): (a) 40; (b) 20%