When 99 is considered higher than 100?

Known by all without exception, Forever here, for your protection, Sometimes strong, sometimes weak, Right after the night I come - hot and chic. And while millions of miles away, I always get to you, I find my way. No life around could do without me, Can you guess what I might be?

A man is looking at a photograph of someone. His friend asks who it is. The man replies, “Brothers and sisters, I have none. But that man’s father is my father’s son.” Who was in the photograph?

If,

A + B = C
D - C = A
E - B = C

Based on the above equations, find out the answer for:

D + F = ?

What has to be broken before you can use it?

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

f you were running a race, and you passed the person in 2nd place, what place would you be in now?

Find the missing letter in the last circle logically in the given below picture.

Two guards were on duty outside a barracks. One faced up the road to watch for anyone approaching from the North. The other looked down the road to see if anyone approached from the South. Suddenly one of them said to the other, "Why are you smiling?"

How did he know his companion was smiling?

John said, "If yesterday was tomorrow, today would be Friday."

When did John make this statement?