Problema Solution
You have vast quantities of yellow brass (67% copper and 33% zinc) and red brass (85% copper and 15% zinc). You receive and order for 500 tons of brass containing 80% copper and 20% zinc. How many tons of each kind of brass would you need to melt together to fill the order?
Answer provided by our tutors
Let
x=amount of yellow brass needed
y=amount of red brass needed
the amount of copper in the yellow brass (0.67x) + amount of copper in the red brass (0.85y) = the amount of copper in the final mixture (0.80*500=400). the same argument goes for the zinc. thus we have the following system of equations
0.67x + 0.85y = 0.80*500
0.33x + 0.15y = 0.20*500
by solving the system of equations we find
x = 138.9 tons of yellow brass
y = 361.1 tons of red brass
click here to see the step by step solution of the system of equations