Question

You are going to mix a gallon bucket of window cleaner. The instructions direct you to mix 1 part cleaner to 3 parts water. How much cleaning solution will you need to use?*

Answer 1

Let amount of cleaner be x gallons.
"1 part cleaner to 3 parts water" implies x gallons of cleaner will need 3x gallons of water.
Total cleaner+water solution is x + 3x = 4x gallons.
"You are going to mix a gallon bucket of window cleaner."
4x = 1 gallons
x = 1/4 gallon.