Question

A foundry has been commissioned to make souvenir coins. The coins are to be made from an alloy that is 40% silver. The foundry has on hand two alloys, one with 50% silver content and one with a 25% silver content. How many kilograms of each alloy should be used to make 10 kilograms of the 40% silver alloy?

Answer 1

the amount of 50% silver alloy is 6 kilograms and the amount of 25% silver alloy is (10-6)= 4 kilograms.

Explanation:

Suppose, the weight of the alloy with 50% silver content is x kilograms.

As, the weight of the mixed alloy should be 10 kilograms, so the weight of the alloy with 25% silver content will be: kilograms

The percentage of silver content in the mixed alloy is 40%. So the equation will be calculated as

`0.5x+0.25(10-x)=0.4*10\\0.5x+2.5-0.25x=4\\0.25x=1.5\\\Rightarrow x=(1.5)/(0.25) = 6`

So, the amount of 50% silver alloy is 6 kilograms and the amount of 25% silver alloy is (10-6)= 4 kilograms.