There is a box full of marbles,
all but two are blue,
all but two are green,
and all but two are red.

How many marbles are in the box?

What number do you get when you multiply all of the numbers on a telephone's number pad?

In the picture, you can see a chess board. On the top left position, the K marks a knight. Now, can you move the knight in a manner that after 63 moves, the knight has been placed at all the squares exactly once excluding the starting square?

What's the next in the series?

H, Be, F, S, Mn, Kr, In, Gd, Tl, ?

John replied, when asked how old he was. In 2 years he will be twice as old as he was five years ago.' How old is he ?

what's the probability of getting a king or a queen from a pack of 52 cards?

What number comes next in the series?

5 15 5 18 5 24 14 20 _

100 prisoners are stuck in the prison in solitary cells. The warden of the prison got bored one day and offered them a challenge. He will put one prisoner per day, selected at random (a prisoner can be selected more than once), into a special room with a light bulb and a switch which controls the bulb. No other prisoners can see or control the light bulb. The prisoner in the special room can either turn on the bulb, turn off the bulb or do nothing. On any day, the prisoners can stop this process and say "Every prisoner has been in the special room at least once". If that happens to be true, all the prisoners will be set free. If it is false, then all the prisoners will be executed. The prisoners are given some time to discuss and figure out a solution. How do they ensure they all go free?

What can you see in the middle of March and April that you can never see in any other month?

2, 3, 5, 9, 17, _ What is the next number in the sequence?