A book store had 260 story books. There were Chinese, English and Malay story books in the ratio of 1 : 8 : 4. When the book store assistant brought in another 88 new story books, the number of Chinese story books was increased by 40% and the number of English story books was increased by ¹₈.

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

	Chinese	English	Malay	Total
Before	1 u	8 u	4 u	260
Change	+ 0.4 u	+ 1 u	+ ?	+ 88
After	1.4 u	9 u	7 u	348

Increase in the number of Chinese story books
= 40% x 1 u
= ⁴⁰₁₀₀ x 1 u
= 0.4 u

Increase in the number of English story books
= ¹₈ x 8 u
= 1 u

Total number of story books at first
= 1 u + 8 u + 4 u
= 13 u

13 u = 260

1 u = 260 ÷ 13 = 20

Increase in the number of Chinese and English story books
= 0.4 u + 1 u
= 1.4 u
= 1.4 x 20
= 28

Number of Malay story books brought in
= 88 - 28
= 60 

(b)
Number of Malay story books at first
= 4 u
= 4 x 20
= 80

Percentage increase in Malay story books
= ⁶⁰₈₀ x 100%
= 75%

Answer(s): (a) 60; (b) 75%