A book store had 120 fiction books. There were English, Malay and Chinese fiction books in the ratio of 1 : 6 : 5. When the book store assistant brought in another 74 new fiction books, the number of English fiction books was increased by 40% and the number of Malay fiction books was increased by ¹₂.

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

	English	Malay	Chinese	Total
Before	1 u	6 u	5 u	120
Change	+ 0.4 u	+ 3 u	+ ?	+ 74
After	1.4 u	9 u	9 u	194

Increase in the number of English fiction books
= 40% x 1 u
= ⁴⁰₁₀₀ x 1 u
= 0.4 u

Increase in the number of Malay fiction books
= ¹₂ x 6 u
= 3 u

Total number of fiction books at first
= 1 u + 6 u + 5 u
= 12 u

12 u = 120

1 u = 120 ÷ 12 = 10

Increase in the number of English and Malay fiction books
= 0.4 u + 3 u
= 3.4 u
= 3.4 x 10
= 34

Number of Chinese fiction books brought in
= 74 - 34
= 40 

(b)
Number of Chinese fiction books at first
= 5 u
= 5 x 10
= 50

Percentage increase in Chinese fiction books
= ⁴⁰₅₀ x 100%
= 80%

Answer(s): (a) 40; (b) 80%