Problema Solution
ten gallons of a 30% acid solution is obtained by mixing a 20% solution with a 50% solution. How much of each must be used?
Answer provided by our tutors
let
x = gallons of the 20% solution
y = gallons of the 50% solution
10 gallons of a 30% acid solution is obtained by mixing x and y therefore
x + y = 10
20% of x + 50% of y = 30% (x+y)
0.2*x + 0.5*y = 0.3*10
by solving the system of equations
x + y = 10
0.2*x + 0.5*y = 0.3*10
we find
x = 20/3 = 6.67 gallons approximately
y = 10/3 = 3.33 gallons approximately
We should use 6.67 gallons of the 20% solution and 3.33 gallons of the 50% solution.