Correct Answer - Option 4 : 13 : 7
Given :
Ratio in A alloy of Gold and Copper = 3 : 2
Ratio in B alloy of gold and copper = 7 : 3
Calculations :
Let 1 kg of mixture is taken
A = 3 : 2 , B = 7 : 3
In A, Gold = 3/5, Copper = 2/5
In B, Gold = 7/10, Copper = 3/10
Required ratio = (3/5 + 7/10) : (2/5 + 3/10)
⇒13/10 : 7/10
⇒ 13 :7
∴ Required ratio is 13 : 7.