Question

An alloy needs to contain between 46% copper and 50% copper. Calculate the least and greatest amounts of a 60% copper alloy that should be mixed with a 40% copper alloy in order to end up with thirty pounds of an alloy containing an allowable percentage of copper.

Answer 1

Answer:

Let x = amount of 60% copper alloy

then

30−x = amount of 40% copper alloy

Considering least amount:

0.60x+0.40(30−x)=0.46(30)

0.60x+12−0.40x=13.8

0.20x+12=13.8

0.20x=1.8

x=9 pounds

Considering greatest amount:

0.60x+0.40(30−x)=0.50(30)

0.60x+12−0.40x=15

0.20x+12=15

0.20x=3

x=15 pounds