Q11. 
An alloy contains zinc, copper and tin in the ratio $2:3:1$ and another contains copper, tin and lead in the ratio $5:4:3$. If equal weights of both alloys are melted together to form a third alloy, then the weight of lead per kg in new alloy will be: 
A.  $\dfrac{1}{10} \text{ kg}$ 

B.  $\dfrac{1}{8} \text{ kg}$ 

C.  $\dfrac{1}{4} \text{ kg}$ 

D.  $\dfrac{1}{2} \text{ kg}$ 