Problema Solution
You need 480 mL of a 70% alcohol solution. On hand, you have a 20% alcohol mixture and a 80% alcohol mixture. How much of each mixture will you need to obtain the desired solution?
Answer provided by our tutors
let
x = ml of 20% alcohol mixture
y = ml of 80% alcohol mixture
you need 480 ml of a 70% alcohol solution
x + y = 480
the % of alcohol in x + the % of alcohol in y = 480 ml of a 70% alcohol
0.20x + 0.80y = 0.70*480
by solving the system of equations
x + y = 480
0.20x + 0.80y = 0.70*480
we find
x = 80 ml
y = 400 ml
click here to see the step by step solution of the system of equations
we must mix 80 ml of 20% alcohol mixture and 400 ml of 80% alcohol mixture to obtain 480 ml of a 70% alcohol solution.