An alloy of zinc and copper contains the metals in the ratio 5 : 3. The quantity of zinc to be added to 6 kg of the alloy so that the ratio of the metal may be 3 : 1 is:	Choose the correct choice:
A) 2
B) 9
C) 8
D) 7
E) 4
Explanation:   In sixteen kg of alloy 10 kg of zinc and 6 kg copper is present   To make the ratio 3:1 we must add 8 kg of zinc to make it 18 kg of zinc and 6 kg copper   So answer is 8.   Answer: 8
<result>C</result>
An alloy of zinc and copper contains the metals in the ratio 5 : 3. The quantity of zinc to be added to 6 kg of the alloy so that the ratio of the metal may be 3 : 1 is: