In 10 kg of 1st alloy the ratio of copper and zinc = 4:1
∴ Copper =45×10kg=8kg Zinc =15×10kg=2kg In 16 kg of 2nd alloy the ratio of copper and zinc = 1:3
∴ Copper =14×16kg=4kg Zinc =34×16kg=12kg
Let x kg be the amount of pure copper added Given Copper : Zinc = 3 : 2 in the new alloy, i.e. (8 + 4 + x) : (2 + 12) = 3 : 2
⇒12+x14=32⇒24+2x=42⇒2x=18⇒x=9kg
∴ Weight of the new alloy = (8 + 4 + 9 + 2 + 12) = 35 kg