Understanding mixture problems Practice Test

If Audrey is currently years old, and Matt’s age is 2 years more than of Audrey’s age, what will be Matt’s age in 5 years?

A scientist needs a 10% saline solution for an experiment. In his closet he finds a 20 ounce bottle of 25% saline solution. How many ounces of pure water should he add to the mixture to produce the correct saline solution?