Ratio Tough Question

[engg.manik]

Question -> Two alloy of Copper & Zinc, in the first alloy the ratio of Copper & Zinc is 3:4, in the second alloy the ratio of Copper & Zinc is 6:1, In what proportion should these two alloys be mixed so that a new alloy containing equal part of Copper & Zinc must be added.

Ans :- > 5:1

Can anyone please help with solution

[a_forest]

Say you need to use x amount of Alloy 1 and y amount of Alloy 2 to balance the Copper and Zinc.

So Copper from Alloy 1 is 3x/7 and from Alloy 2 6y/7.
Zinc from Alloy 1 is 4x/7 and from Alloy 2 y/7.

It follows that 3x+6y=4x+y or x=5y or so the ration is 5:1 (x:y).