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

O T T F F S S ?

If it took eight men ten hours to build a wall, how long would it take four men to build it?

A boy and a girl are sitting on the porch.
"I'm a boy," says the child with black hair.
"I'm a girl," says the child with red hair.
If at least one of them is lying, who is which?

You have two buckets of 11 liters and 6 litres.
How can you measure exactly 8 litres?

A professor thinks of two consecutive numbers between 1 and 10.
'A' knows the 1st number and 'B' knows the second number

A: I do not know your number.
B: Nor do I know your number.
A: Now I know.

What are the four solutions for this?

Identify Me

Hint1: I am a god
Hint 2: I am a planet
Hint 3: measurer of heat

You want to boil a two-minute egg. If you only have a three-minute timer (hourglass), a four-minute timer and a five-minute timer, how can you boil the egg for only two minutes?

As you can see that fifteen matches have been used to form an arrangement. What you have to do is remove any six of them to make them ten.

What is the next number?

77, 49, 36, 18 ?

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?