How many gallons of a 60% antifreeze solution must be mixed with 60 gallons of 20% antifreeze to get a mixture that is 50% antifreeze?

Question

Use the six-step method.

Answer 1

I am not sure what the 6 step method is? This problem is a weighted average problem with the following format.

Let x = gallons of the 60% solution

Then,

{ x(60%) + 60(20%) }/(x + 60) = 50%

When you solve for x:

10%x = 1800% or x = 180 gallons of the 60% solution