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?

Four people need to cross a rickety bridge at night. Unfortunately, they have only one torch and the bridge is too dangerous to cross without one. The bridge is only strong enough to support two people at a time. Not all people take the same time to cross the bridge. Times for each person: 1 min, 2 mins, 7 mins and 10 mins. What is the shortest time needed for all four of them to cross the bridge?

If I remove one from eleven it becomes Ten and if I remove one from nine also becomes Ten. How?

Look at the below sequence of letters and tell us what the next letter should be:

O T T F F S S ?

Count the number of squares in the picture below.

At a party, there are five people and a whole round cake lying at the centre of the table. Only four people will make a cut and take their piece and the last one will get the remaining piece on the table. How can they make sure that everyone gets a 1/5th of the piece?

If two fifty-foot ropes are suspended from a forty-foot ceiling that is twenty feet apart, how much rope will you be able to steal if you have a knife?

Consider all the numbers between 1 and 1 million. Among all these numbers, there is something very special about the number 8 and the number 2202. What is it?

Can you calculate the probability of getting a sum of six when a dice is thrown twice?

Can you find out which number multiplied by itself will give the output as 12345678987654321?