Question

An alloy of gold, silver and bronze weighs 200 grams. If gold, silver and bronze in the alloy are in ratio 3 : 4 : 3, then how much percentage of silver, as compared to the initial amount of silver, must be added such that their weights are in ratio 1 : 2 : 1 in the final alloy?

Answer 1

Answer:

Since we are working for %, we can assume some value for the initial alloy..

So let's take it 100 and B:G:S is 90:7:3

Now another alloy, A, is added to it and gold becomes 5% BUT the gold is not added at all..

So 7 becomes 5% of new total . .......5% of total = 7.... total = 7*100/5=140

Thus new alloy,A, added = 140-100=40

Now let's concentrate on the bronze..

Bronze is 85% of new total = 140*85/100=119

So increase in bronze=119-90=29=quantity of bronze in new alloy,A.

So % of bronze in A=100*29/40=72.5%