How many people must be gathered together in a room, before you can be certain that there is a greater than 50/50 chance that at least two of them have the same birthday?

Take away my first letter, then take away my second letter. Then take away the rest of my letters, yet I remain the same. What am I?

You enter your friend's room. He is not in his room. Although you see that on the bed there are two dogs, five cats, two giraffes and three pigs. Also, a couple of chickens and ducks are flying in the room.

Calculate the number of legs standing on the floor.

Can you arrange four 9's and use at most 2 math symbols, to make the total 100?

Next Number in the Series,

5, 16, 49, 104, ?

Rearrange the letters in "new door" to make one word.

There is one thing that goes round the house and also inside the house but never even share a brief touch. What is it?

Can you make numbers like 24, using numbers 3,3,7 & 7 with any arithmetic operator?

You have a roll of cloth 1km long. You have a machine which cuts this roll into pieces of 10-meter-long cloth.

How long would it take for the machine to cut the roll if each cut took 4 secs?

Can you find the least possible number such that

If the number is divided by 3, it gives the remainder of 1;
If the number is divided by 4, it gives the remainder of 2;
If the number is divided by 5, it gives the remainder of 3;
If the number is divided by 6, it gives the remainder of 4.