Hope this helps!
Sorry the writing is really bad looking its hard to write on a laptop.
Answer:
Each friend gets
of the popcorns.
Step-by-step explanation:
Nathalie's brother takes 1/5 of the popcorn for himself.
so there is ( 1 - 1/5)
= 4/5 of the popcorns left in the bowl
including Nathalie and her 3 friends, there are (3 + 1) = 4 persons.
So, each friend gets

=
of the popcorns