A book shop had 180 story books. There were English, Malay and Chinese story books in the ratio of 3 : 7 : 8. When the book shop assistant brought in another 88 new story books, the number of English story books was increased by 60% and the number of Malay story books was increased by ³₇.

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

	English	Malay	Chinese	Total
Before	3 u	7 u	8 u	180
Change	+ 1.8 u	+ 3 u	+ ?	+ 88
After	4.8 u	10 u	12 u	268

Increase in the number of English story books
= 60% x 3 u
= ⁶⁰₁₀₀ x 3 u
= 1.8 u

Increase in the number of Malay story books
= ³₇ x 7 u
= 3 u

Total number of story books at first
= 3 u + 7 u + 8 u
= 18 u

18 u = 180

1 u = 180 ÷ 18 = 10

Increase in the number of English and Malay story books
= 1.8 u + 3 u
= 4.8 u
= 4.8 x 10
= 48

Number of Chinese story books brought in
= 88 - 48
= 40 

(b)
Number of Chinese story books at first
= 8 u
= 8 x 10
= 80

Percentage increase in Chinese story books
= ⁴⁰₈₀ x 100%
= 50%

Answer(s): (a) 40; (b) 50%