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:
5 kg
2 kg
3 kg
4 kg
Explanation:
In 6kg of alloy 15/4-zinc and 9/4-copper.
So, let extra zinc added be x.
=> (15/4+x)/ (9/4) =3/1.
=> x=3.