Answer: 100 ounces of the alloy.
Step-by-step explanation: To solve, we create an equation:
First, though, let's define some variables and values -
x = amount of the alloy we are trying to find
0.3 = 30% copper
0.6 = 60% copper
50 = 50 ounces of the alloy
0.3(x) + 0.6(50) = 0.4(x+50) - original equation
0.3x + 0.6*50 = 0.4x + 0.4*50 - expanded
subtract 0.3x and 0.4*50 on both sides to get...
0.2*50 = 0.1x - simplified
calculate...
10 = 0.1x - simplified
divide both sides by 0.1 to get...
100 = x --> x = 100