They start with 34.25
They plan to use 15.5
They want to use the remaining for 5 portions
First let's see how much we have left after we use the 15.5 pounds
34.25 - 15.5 = 18.75 pounds
So, we have 18.75 pounds remaining. We want to divide this into 5 portions
18.75 / 5 = 3.75
So, you will have 3.75 pounds in each portion.