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

You are given four results as below:
1111 = F
2222 = E
3333 = T
Then, can you find out how to code 4444?

Find the next number in the series below.

6 18 270 72090 ?

What are the 50th, 63rd and 100th numbers in the sequence below?
4, 5, 8, 8, 9, 9, 12, 13, 13, 13, 17, 18, ...

What's the next in the series?

H, Be, F, S, Mn, Kr, In, Gd, Tl, ?

Find out which of the given views in the picture is accurately the top view of the given pyramid.

A Car driver was heading down a street in Washington. He went right past a stop sign without stopping, he turned left where there was a 'no left turn' sign and he went the wrong way on a one-way street. Then he went on the right side of the road past a cop car. Still, he didn't break any traffic laws. Why not?

A boy and his father are caught in a traffic accident, and the father dies. Immediately the boy is rushed to a hospital, suffering from injuries. But the attending surgeon at the hospital, upon seeing the boy, says 'I cannot operate. This boy is my son.' How is this situation explained?

No one wants to have it, but if one got it, he does not want to lose it. What is It?

With the help clues provided in the image, can you find the 5 digit key?