What runs around the whole yard without moving?

If two's company, and three's a crowd, then whats four and five ?

What is the four-digit number in which the first digit is one-third the second, the third is the sum of the first two, and the last is three times the second?

What number comes next in this sequence:
7 8 5 5 3 4 4 _

1 + 9 + 8 = ?
considering, 28 + 8 + 92 = 10

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?

What English word has three consecutive double letters?

John is the son of Jacob.
So,
Jacob is the_____of John's father?

No matter how little or how much you use me, you change me every month. What am I?

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?