A shop had 1020 story books. There were Malay, Chinese and English story books in the ratio of 6 : 3 : 8. When the shop assistant brought in another 372 new story books, the number of Malay story books was increased by 20% and the number of Chinese story books was increased by ¹₃.

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

	Malay	Chinese	English	Total
Before	6 u	3 u	8 u	1020
Change	+ 1.2 u	+ 1 u	+ ?	+ 372
After	7.2 u	4 u	12 u	1392

Increase in the number of Malay story books
= 20% x 6 u
= ²⁰₁₀₀ x 6 u
= 1.2 u

Increase in the number of Chinese story books
= ¹₃ x 3 u
= 1 u

Total number of story books at first
= 6 u + 3 u + 8 u
= 17 u

17 u = 1020

1 u = 1020 ÷ 17 = 60

Increase in the number of Malay and Chinese story books
= 1.2 u + 1 u
= 2.2 u
= 2.2 x 60
= 132

Number of English story books brought in
= 372 - 132
= 240 

(b)
Number of English story books at first
= 8 u
= 8 x 60
= 480

Percentage increase in English story books
= ²⁴⁰₄₈₀ x 100%
= 50%

Answer(s): (a) 240; (b) 50%