What does this mathematical rebus means ?

Two-person want to cross a river. Only one boat is present on the riverside that can carry only one person at a time.

However, they still manage to cross the river. How is it possible?

A pond had 60 fish, out of which, all but 20 died.
How many fishes are now present in that pond?

This is a classy optical illusion puzzle. What more you can find except bricks in the image below?

I speak without a mouth, and hear without ears. I have no-body, but I come alive with the wind. What am I?

f you were running a race, and you passed the person in 2nd place, what place would you be in now?

Three ants are sitting at the three corners of an equilateral triangle. Each ant starts randomly picks a direction and starts to move along the edge of the triangle. What is the probability that none of the ants collide?

How many letters are in the alphabet?

Always in you, Sometimes on you;

If I surround you, I can kill you.

What am I?

A boy was at a carnival and went to a booth where a man said to the boy, "If I write your exact weight on this piece of paper then you have to give me $50, but if I cannot, I will pay you $50." The boy looked around and saw no scale so he agrees, thinking no matter what the carny writes he'll just say he weighs more or less. In the end the boy ended up paying the man $50. How did the man win the bet?