The Little ant seems to be always confused. Do you know why?

What does this rebus means ?

PROG WORKRESS

In a university, a professor gave a set of three problems to the three brilliant students of his class. See the image for the questions.

Who can jump higher than a Mountain?

Find the next number in the series below.

6 18 270 72090 ?

A man has to get a fox, a chicken, and a sack of corn across a river.

He has a rowboat, and it can only carry him and one other thing.
If the fox and the chicken are left together, the fox will eat the chicken.
If the chicken and the corn are left together, the chicken will eat the corn.

How does the man do it?

If you drop me I’m sure to crack, but give me a smile and I’ll always smile back. What am I?

I am a type of word that is spelt incorrectly or used differently, on purpose for humour. What am I?
Hint 1: You can find me in a joke.
Hint 2: I am a play on words.

What number comes next in the series?

5 15 5 18 5 24 14 20 _

Can you solve this picture maths equation?