Bonnie has one alloy containing 23% aluminum and another containing 45% aluminum. How many pounds of each alloy must he use to make 58 pounds of a third alloy containing 42% aluminum?

Question

anonymous · Answer

You can work this out using a system of equations.

x represents the pounds of alloy 1
y represents the pounds of alloy 2
x + y = 58 (the number of pounds of each allow to make 58 pounds)

0.23x + 0.45y = 0.42 x 58 (the amount of aluminum in the first, second and resulting alloy.

anonymous · Answer

The second equation is easier to work with if you multiply through by 100 to get rid of the decimals. In other words, 

23x + 45y = 2436

From the first equation x = 58 - y

Substitute that into the second equation and you will find your answer. Don't forget to check the answer. It ends up being a decimal.