In the four images below, can you find the odd one out?

It comprises roots which nobody sees,
Much taller than those trees,
Up and up it goes,
Still it never grows?

There was once a college that offered a class on probability applied to the real world. The class was relatively easy, but there was a catch. There were no homework assignments or tests, but there was a final exam that would have only one question on it. When everyone received the test paper it was a blank sheet of paper with a solitary question on it: 'What is the risk?'.Most students were able to pass, but only one student received 100% for the class! Even stranger was that he only wrote down one word!
What did he write?

What can jump higher than a building?

Trying to tease Birbal, Akbar gave him one gold coin and ask him to buy
* something for him to eat
* something for him to drink.
* something to feed the cows
* something to plant in the garden
and most important you need to buy only one thing.

What must Birbal buy to silence Akbar?

Prove that twice of ten is the same as twice of eleven.

Do You See It?

You are given four tennis balls and asked to arrange those balls in a manner that the distance between each one of them is exactly equal. How will you do it?

Why do people go to bed?

What is the riddle which can be asked all day with a different correct answer each time.