How is a fly different from a mosquito?

A girl has as many brothers as sisters, but each brother has only half as many brothers as sisters. How many brothers and sisters are there in the family?

I have four wings but can't fly.
I express no emotions.
I am found on the exact spot every time you look.
I keep toiling away with a little sound.

Do you know what am I?

If eleven plus two equals one, what does nine plus five equal?

When monkey rotate the gear, which mark will be hit 1 or 2 ?

The teacher told the student that if he told a lie then he will be expelled from school and if he told the truth then he still is expelled from school.

What can a student say to prevent his being expelled from school?

A mile-long train is moving at sixty miles an hour when it reaches a mile-long tunnel. How long does it take the entire train to pass through the tunnel?

On her drawing table, Sayna lit 12 coloured candles. A few seconds later she blew two candles off.

How many candles Sayna have at the end?

There are are five things wrong with this sentence; only geniuses will be able to to spot all of the mitstakes

A person was killed at a house party. When the police arrive, there are six people present in the house who are the friends of the victim. The name of the friends is Rohit, Aman, Nick, Gagan, and Randy.

Near the dead body, they find a few numbers written with blood by the victim on the floor. The numbers are 8, 5, 4, and 11.

The police arrests one of the friends for the murder. Whom did they arrest and why?