Answer:
16 kg of I type and 64 kg of II type should be mixed.
Explanation:
Given that a metal alloy in original has 20% copper and 80% other metals.
Another mixture contains 60% copper and 40% other metals.
We have to get a new alloy of 80 kg which has 52% copper.
Let us assume that we mix x kg of I alloy and y kg of second alloy.
Then we have x+y = total weight = 80 kg.
x+y = 80 ... (i)
Next condition is that new alloy has 52% copper in it
When we mix x kg of I, and y kg of II, copper content would be
0.2x+0.6y. This equals 52% of 80 = 41.6
Or Dividing by 0.2 we get
x+3y =208 ... (ii)
(ii)-(i) gives 2y = 128 or y =64 kg
x = 16 kg
16 kg of I type and 64 kg of II type should be mixed.
Verify:
Copper in new alloy = 16(0.2) + 64(0.6) = 3.2+38.4 = 41.6
= 52% of 80