A metal worker had a metal alloy that is 25% copper and another alloy that is 70% copper. How many kilograms of each alloy should the metalworker combine to create 100kg of a 52% copper alloy ?

Answer 1

(x kg)(25) + (100 kg - x kg)(70) = (100 kg)(52)

25x + 7000 - 70x = 5200

-45x = -1800

x = 40 kg of the 25% alloy

100 kg - 40 kg = 60 kg of the 70% alloy