1.  The proportion of Zinc and Copper in a brass piece is 13 : 7. How much zinc will be there in 100 kg of such a piece?
A. 20 kg
B. 35 kg
C. 55 kg
D. 65 kg

Answer: Option D

Explanation:

∵ 20 kg of brass contains zinc = 13 kg
∴ 100 kg of brass contains zinc = (13/20) x 100 kg. = 65 kg.