An alloy is to contain copper and zinc in the ratio 5:3. The zinc required to be melted with 40kg of copper is?	Select: A) 15 kg B) 20 kg C) 8 kg D) 24 kg E) 32 kg

Rationale: let the required quantity of copper be x kg 5 : 3 : : 40 : x 5 x = 40 * 3 x = 24 kg answer is d
Answer: D