A store had 315 comics. There were English, Malay and Chinese comics in the ratio of 2 : 3 : 4. When the store assistant brought in another 112 new comics, the number of English comics was increased by 60% and the number of Malay comics was increased by ¹₃.

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

	English	Malay	Chinese	Total
Before	2 u	3 u	4 u	315
Change	+ 1.2 u	+ 1 u	+ ?	+ 112
After	3.2 u	4 u	5 u	427

Increase in the number of English comics
= 60% x 2 u
= ⁶⁰₁₀₀ x 2 u
= 1.2 u

Increase in the number of Malay comics
= ¹₃ x 3 u
= 1 u

Total number of comics at first
= 2 u + 3 u + 4 u
= 9 u

9 u = 315

1 u = 315 ÷ 9 = 35

Increase in the number of English and Malay comics
= 1.2 u + 1 u
= 2.2 u
= 2.2 x 35
= 77

Number of Chinese comics brought in
= 112 - 77
= 35 

(b)
Number of Chinese comics at first
= 4 u
= 4 x 35
= 140

Percentage increase in Chinese comics
= ³⁵₁₄₀ x 100%
= 25%

Answer(s): (a) 35; (b) 25%