A certain compound is a mixture of two concentrations of iron which are 44% and 29%. How many pounds of each concentration must be used to form 50 lbs.of compound having 38% iron?
With any math problem, you need to have an idea of what your answer should or should not be. In this case, a 44% and a 29% are
used to form a 38% compound. The 44% compound is closer to the end result (38%) than the 29% compound is. Therefore, we know,
for certain that more of the 44% compound should be mixed to form the 38% compound.
Let the amount of 44% compound to be mixed be F
Then amount of 29% compound to be mixed = 50 - F
We then get: .44F + .29(50 - F) = .38(50)
.44F + 14.5 - .29F = 19
.44F - .29F = 19 - 14.5
.15F = 4.5
F, or amount of 44% compound to be mixed = , or
Amount of 29% compound to be mixed: 50 - 30, or