Abox contains 16 cherry fruit chews, 15 peach fruit chews, and 12 plumford choose. which two flavors are in the ratio 5 to 4?

A couple of different ways to solve this.

Build ratio 5/4
Multiply by 2/2 to get equivalent, which is 10/8 - this does not match any possible solution.
Now do 5/4 * 3/3 to get 15/12.  This works, so the answer is 15 peach fruit chews/12 plumb fruit chews.

Trial and error method.