Question

How much pure antifreeze should i put to my to 12 L of a 40% solution from my car to obtain a 60% solution. (the box says that pure antifreeze is 100% = 1.) what question to i make to solve this?

Answer 1

x = amount of 100% solution
y = amount of 60% solution

First we need to determine how much antifreeze there is:
1.00x + 0.40*12 = 0.60y

Now the total amount of solution is:
x + 12 = y

Solve the two equations simultaneously.