In an alloy, the ratio of copper and zinc is 5 : 2. If 1.250 kg of zinc is mixed in 17 kg 500 g of alloy, then the ratio of copper and zinc in the alloy will be -

A. 1 : 2

B. 2 : 1

C. 2 : 3

D. 3 : 2

Answer: Option B

Solution(By Examveda Team)

Quantity of copper in 17.5kg of alloy
$$\eqalign{ & = \left( {17.5 \times \frac{5}{7}} \right){\text{kg}} \cr & = 12.5{\text{kg}}. \cr} $$
Quantity of zinc in 17.5kg of alloy
$$\eqalign{ & = \left( {17.5 \times \frac{2}{7}} \right){\text{kg}} \cr & = 5{\text{kg}} \cr & \therefore {\text{Required ratio}} \cr & = 12.5:\left( {5 + 1.25} \right) \cr & = 12.5:6.25 \cr & = 2:1 \cr} $$