Can you find a pattern and the missing number in the series given below?

100, 155, 258,? , 584, 819.

Look at the below sequence of letters and tell us what the next letter should be:

O T T F F S S ?

A father's child, a mother's child, yet no one's son.

Who am I?

What does this rebus mean?

O
N
C
E
TIME

Every words stands for unique digit that makes the arithmetic equation true

SEVEN + SEVEN + SIX = TWENTY.

What are the digits ?

The more it dries, the wetter it becomes. Can you tell what it is?

I am something people love or hate. I change peoples appearances and thoughts. If a person takes care of them self I will go up even higher. To some people I will fool them. To others I am a mystery. Some people might want to try and hide me but I will show. No matter how hard people try I will Never go down. What am I?

In the Chess Board picture below white army is arranged. You need to add a black army on the board such that no piece is under any threat.
Note: Army comprised of 1 king, 1 queen, 2 rooks, 2 bishops, 2 knights, and 8 pawns.

Decode the movie name from the below picture?

I have Rs.50 and I spend it in the way as below.