Replace the question mark with the number below given a simple math problem.

What is in seasons, seconds, centuries and minutes but not in decades, years or days?

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

Can you think of a smallest +ve number such that if we shuffle the digits of the number, the new number becomes double the original number?

I noticed one of the words in the oxford dictionary is spelled incorrectly. What about you?

I am the largest in my family of fifty.
The youngest of our family lives separately from the rest of the family and so do I.
I am regarded as harsh and tough.
I am so large, you cut me in two equal halves,
each half would still be larger than the second largest member of the family.
Who am I?

Solve the following series:
AZ, GT, MN, __, YB

A chicken farmer has figured out that a hen and a half can lay an egg and a half in a day and a half. How many hens does the farmer need to produce one dozen eggs in six days?

Assume there are approximately 5,000,000,000 (5 billion) people on Earth. What would you estimate to be the result, if you multiply together the number of fingers on every person's left hand? (For the purposes of this exercise, thumbs count as fingers, for five fingers per hand.) If you cannot estimate the number then try to guess how long the number would be.

What famous saying does this rebus mean?

COME SERVED <---
COME SERVED
COME SERVED
COME SERVED
COME SERVED