Can you find out the missing number in the grid?

Can you find the missing letter in the sequence?
S - T - I - L - ? - T - F - Y - C

Below toothpicks/matchsticks indicate the group of fishes moving from west to east direction. Can you make them move from east to west by just moving three toothpicks/matchsticks?

How could a baby fall out of a twenty-story building onto the ground and live?

You may enter, but you may not come in. I have space, but no room. I have keys, but open no lock. What am I?

He digs out tiny caves and stores gold and silver in them. He also built bridges of silver and made crowns of gold. They are the smallest you could imagine. Sooner or later everybody needs his help, yet many people are afraid to let him help them. Who is he?

A dying old man wants to divide his entire land between his only two sons. Since his only wish is to treat them as equal as both of them have been too good to him, he wants to divide his land equally between them. The problem is that the land is significantly irregular in shape and thus there is no choice of cutting them into two equal halves.

Can you help him divide the land in a manner that both of his sons will be happy?

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

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

Decode below three cipher riddles:

26 L of the A
7 D of the W
1000 Y in a M

Using mathematical symbols like +, -, and x in order to make the equations correct. Replace # with the above-given symbols.

9 # 8 # 7 # 6 # 5 # 4 = 91