When I got four, I have it none.
When I got two, I have it some.
When I got none, I have it all.

What is it?

What can run but never walks, has a mouth but never talks, has a head but never weeps, has a bed but never sleeps?

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

Can you place six X (crosses) in below board without making three in a row in any way ?

I am a white box having no key or lid.
Yet there is a golden treasure inside it.

What Am I?

John speaks the truth only once a day in a week. Below are a few hints for you:

First: Days are Sunday, Monday and so on.
Second: One day he says, "I lie on Monday and Tuesday".
Third: On the next day, he says, "Today is either Thursday, Saturday or Sunday".
Fourth: On the next day, he says, "I lie on Wednesday and Friday".

Can you identify the day on which he speaks the truth?

A river should be crossed by a father, a mother and their two sons and two daughters.
There are some rules that should be followed while crossing the river. There can be only two people in the raft while crossing. The daughters cannot be with their father unless there is the presence of the mother. The sons cannot be with their mothers unless the father is present. Unless the guard is on the board, the criminals cannot be with any of the family members. Only the adults like the father, the guard, and the mother knows to use the raft.

How will they cross the river?

How can you drop a raw egg from a height onto a concrete floor without cracking it?

81 x 9 = 801. What must you do to make the this equation true?

Eight of us go fourth, not back, to protect our king from an attack. What are we?