Answer:
4 bags
Step-by-step explanation:
Since there were five in total, and each got 4/5 evenly, it's just basic adding while subtracting the amount from the other bags.
So to get 5/5, which is a full bag, you take portions out of the others to create a full one. Write out 4/5, five times, and then subtract the needed portions from a separate bag to combine a full one.