Question

In two alloys, copper and zinc are related in the ratios of 4 : 1 and 1 : 3. 10 kg of 1st alloy, 16 kg of 2 nd alloy and some of pure copper are melted together. An alloy was obtained in which the ratio of copper to zinc was 3 : 2. Find the weight of the new alloy

Answer 1

Answer:

So, this is how I went about this problem:

If there is 10 kg of the first alloy and the ratio is 4:1, there is 8 kg of copper for 2 kg of zinc

Similarly, for 16 kg of the second alloy and ratio of 1:3, there is 4 kg of copper for 12 kg of zinc

We need a new alloy in which the ratio of copper to zinc is 3:2(3x:2x)

Since we can add pure copper to this mixture and get the new alloy with the 3:2 ratio,

8+4+x/2+12 = 3/2 -> 42 = 2(12+x) -> x = 9

When we add 9 kg of pure copper, the resulting weight of the new alloy will be 10+16+9 = 35kg