What are the next two letters in the following series and why?
W A T N T L I T F S _ _

*Hint: Check Puzzle Title

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

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

What does this rebus mean?

O
N
C
E
TIME

We have arranged an array of numbers below. What you have to do is use any kind of mathematical symbol you know excluding any symbol that contains a number like cube root. You can use any amount of symbols but you have to come up with a valid equation for all of them.

0 0 0 = 6
1 1 1 = 6
2 + 2 + 2 = 6
3 3 3 = 6
4 4 4 = 6
5 5 5 = 6
6 6 6 = 6
7 7 7 = 6
8 8 8 = 6
9 9 9 = 6

I sleep during the day and fly at night, but I have no feathers to aid my flight. What am I?

Can you count the number of triangles in the picture below?

When is the top of a mountain similar to a savings account?

I make a loud sound when I’m changing. When I do change, I get bigger but weigh less. What am I?

What is the fewest number of coins that would be required in order to make sure each and every coin touches exactly three other coins?

Sherlock breaks into a crime scene. The victim is the owner who is slumped dead on a chair and have a bullet hole in his head. A gun lies on the floor and a cassette recorder is found on the table. On pressing the play button, Sherlock hears the message 'I have committed sins in my life and now I offer my soul to the great Lord' and followed a gunshot Sherlock smiles and informed the police that's its a murder.

Why did he think so?