A book store had 160 comics. There were English, Malay and Chinese comics in the ratio of 3 : 8 : 5. When the book store assistant brought in another 66 new comics, the number of English comics was increased by 20% and the number of Malay comics was increased by ¹₄.

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

	English	Malay	Chinese	Total
Before	3 u	8 u	5 u	160
Change	+ 0.6 u	+ 2 u	+ ?	+ 66
After	3.6 u	10 u	9 u	226

Increase in the number of English comics
= 20% x 3 u
= ²⁰₁₀₀ x 3 u
= 0.6 u

Increase in the number of Malay comics
= ¹₄ x 8 u
= 2 u

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

16 u = 160

1 u = 160 ÷ 16 = 10

Increase in the number of English and Malay comics
= 0.6 u + 2 u
= 2.6 u
= 2.6 x 10
= 26

Number of Chinese comics brought in
= 66 - 26
= 40 

(b)
Number of Chinese comics at first
= 5 u
= 5 x 10
= 50

Percentage increase in Chinese comics
= ⁴⁰₅₀ x 100%
= 80%

Answer(s): (a) 40; (b) 80%