What amount of a 65% acid solution must be mixed with a 25% solution to produce 600 mL of a 55% solution?

Answer 1

This can be solved using a system of two equations and two variables.

Let x = amount of mL the 65% acid solution

Let y = amount in mL of the 25% acid solution

We know the total mL's of the mixture of the two solutions is 600 mL,,, so x + y = 610

65% of solution x is acid which can be written as .65 x and similarly acid from second solution can be written as .25 y. We know that 55% of the 610 mL solution will be acid or .55 (610).

The acid in mixture solution comes from the acid in solution x and solution y. So .65 x + .25 y = .55 (610)

We now have system of equations to solve

x + y = 610

.65 x + .25 y = .55 (610)

From here solve the system using substitution or elimination.