A shop had 960 story books. There were Chinese, English and Malay story books in the ratio of 3 : 8 : 5. When the shop assistant brought in another 576 new story books, the number of Chinese story books was increased by 20% and the number of English story books was increased by ³₄.

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

	Chinese	English	Malay	Total
Before	3 u	8 u	5 u	960
Change	+ 0.6 u	+ 6 u	+ ?	+ 576
After	3.6 u	14 u	8 u	1536

Increase in the number of Chinese story books
= 20% x 3 u
= ²⁰₁₀₀ x 3 u
= 0.6 u

Increase in the number of English story books
= ³₄ x 8 u
= 6 u

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

16 u = 960

1 u = 960 ÷ 16 = 60

Increase in the number of Chinese and English story books
= 0.6 u + 6 u
= 6.6 u
= 6.6 x 60
= 396

Number of Malay story books brought in
= 576 - 396
= 180 

(b)
Number of Malay story books at first
= 5 u
= 5 x 60
= 300

Percentage increase in Malay story books
= ¹⁸⁰₃₀₀ x 100%
= 60%

Answer(s): (a) 180; (b) 60%