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?

John was driving a bus and got stuck when passing through an underpass. Then came Jacob with a needle and got the bus out of the underpass.

What did the boy do?

Can anyone tell me a word in the English dictionary which has a silent 'z'?

Move three sticks of the spiral below to form a square.

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

We know that the number 7 is the prime followed by a cube. Which next number is also a prime followed by a cube?

What does this mean?

CCCCCCC

I am a type of vehicle that has two wheels and is powered by humans. What am I?
Hint 1: You can ride me for exercise.
Hint 2: I am environment-friendly.

If eleven plus two equals one, what does nine plus five equal?

There is a barrel with no lid and some wine in it. 'This barrel of wine is more than half full,' said Curly. 'No it's not,' says Mo. 'It's less than half full.' Without any measuring implements and without removing any wine from the barrel, how can they easily determine who is correct?