A student pushes on a crate with a force of 100 N directed to the right. What force does the crate exert on the student?

The Force exerted on the student by crate will be 100 N.

Explanation:

As per the given Question student is trying to push the crate in right direction with the force of 100N.

And we know that, Newton's third law states that every action has equal and opposite reaction.

So from the Newton's 3rd law of motion it is very clear the student must be experiencing the same amount of force which he is applying.