Question

A 25% vinegar solution is combined with triple the amount of a 45% vinegar solution and a 5% vinegar solution resulting in 20 milliliters of a 30% vinegar solution.

Write an equation that models this situation and explain what each part represents in the situation. Then solve the equation and find the amount of each of the solutions that were combined.

Please help. We didn't really talk that much about these types of problems and I'm confused.

Answer 1

You are dealing with 2 concepts.
1. The volume of the two liquids. The concentration of vinegar in each one

let the volume of the 45% stuff be x litres
then the volume of the 25% stuff is 3x L
let the volume of the 5% stuff be y L

x+3x+y = 20
y = 20 - 4x

Now to the concentrion:
.45x + .25(3x) + .05(20-4x) = .3(20)
times 100
45x + 25(3x) + 5(20-4x) = 600

solve for x, then back-substitute
notice how much of the 5% vinegar is needed !!

Answer 2

Thanks, been having trouble with that question too.