Question

How much of a 75% copper alloy should be melted into 62 kg of a 35% copper alloy to produce an alloy which is 50% of copper?

Answer 1

`37.2` kgm

Explanation:

Let the amount of 75% copper alloy be `x` kgm.
then the total weight of the 50% alloy produced will be `x+62` kgm

The total copper in the combined alloy will be
`color(white)("XXXX")` `(0.75)x + (0.35)(62) = (0.50)(x+62)` kgm

`color(white)("XXXX")` `75x + 2170 = 3100 + 50x`

`color(white)("XXXX")` `25x = 930`

`color(white)("XXXX")` `x= 37.2`