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?

I am a prime number.
The double of myself is equal to the square of me.

which number am I?

I am beautiful, up in the sky. I am magical, yet I cannot fly. To people I bring luck, and to some people, riches. The boy at my end does whatever he wishes. What am I?

Before Mount Everest was discovered, what was the highest mountain in the world?

I had an infinite supply of water and 5 litres and 3 litres jars.

How would you measure exactly 4 litres in the least number of steps?

A word I know,
Six letters contain,
Subtract just one,
And twelve is what remains.

Can you fill the blank with the correct number?

6 30 870 756030 _____

John can fit six large chocolate boxes or nine small chocolate boxes into a carton. How many cartons will he require to put sixty-six chocolate boxes into?

Find The Next Number In The Sequence

30 10 15 13 0 16 -15 ?

Two girls were born to the same mother, on the same day, at the same time, in the same month and year and yet they're not twins. How can this be ?