Lenardo Mixes an alloy containing 4% sliver with an alloy containing 1% sliver to make 60 pounds of an alloy with 2% sliver. How many pound each were used?

Question

another one to solve :)  ......

Answer 1

Let x = amount of 4% silver

y = amount of 1% silver

then

0.04x + 0.01y = 0.02*60 = 1.2

x+y = 60 or y = 60 - x

substitute this into first eqn

0.04x + 0.01(60-x) = 1.2

0.03x +0.6 = 1.2

0.03x = 0.6

x = 20 lbs of 4% silver

y = 60-x = 60-20 = 40 lbs of 1% silver