You have

apples left.
You have 5 whole apples, you took one whole apple out, which equals 4 whole apples left. Then with the whole apple you took out, you ate

of it.
Jack ate
of an apple in 5 apples. If you say that Jack ate

of 3 apples, then he ate

apples. So there isn't any difference when he ate

of an apple.
A is the answer because the number 8 is a constant. and the multiplication sign is the operator.
The answer is B (Sorry for the bad handwriting.)
I believe this answer is greater than