A book shop had 850 comics. There were English, Malay and Chinese comics in the ratio of 6 : 7 : 4. When the book shop assistant brought in another 410 new comics, the number of English comics was increased by 20% and the number of Malay comics was increased by ⁶₇.

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

	English	Malay	Chinese	Total
Before	6 u	7 u	4 u	850
Change	+ 1.2 u	+ 6 u	+ ?	+ 410
After	7.2 u	13 u	5 u	1260

Increase in the number of English comics
= 20% x 6 u
= ²⁰₁₀₀ x 6 u
= 1.2 u

Increase in the number of Malay comics
= ⁶₇ x 7 u
= 6 u

Total number of comics at first
= 6 u + 7 u + 4 u
= 17 u

17 u = 850

1 u = 850 ÷ 17 = 50

Increase in the number of English and Malay comics
= 1.2 u + 6 u
= 7.2 u
= 7.2 x 50
= 360

Number of Chinese comics brought in
= 410 - 360
= 50 

(b)
Number of Chinese comics at first
= 4 u
= 4 x 50
= 200

Percentage increase in Chinese comics
= ⁵⁰₂₀₀ x 100%
= 25%

Answer(s): (a) 50; (b) 25%