What is black when you buy it, red when you use it, and gray when you throw it away?

One evening there was a murder in the home of a married couple, their son and daughter. One of these four people murdered one of the others. One of the members of the family witnessed the crime.

The other one helped the murderer.

These are the things we know for sure:

1. The witness and the one who helped the murderer were not of the same sex.

2. The oldest person and the witness were not of the same sex.

3. The youngest person and the victim were not of the same sex.

4. The one who helped the murderer was older than the victim.

5. The father was the oldest member of the family.

6. The murderer was not the youngest member of the family.

Who was the murderer?

You can take four of the five letters out of this word, but the pronunciation never changes. What is the word?

Can you move 2 matchsticks to form four equal sized squares.

Count the number of triangles in the given picture.

A rubber ball keeps on bouncing back to 2/3 of the height from which it is dropped. Can you calculate the fraction of its original height that the ball will bounce after it is dropped and it has bounced four times without any hindrance ?

People put me on the table and cut me but do not eat me. What am I?

Can you name four days which start with the letter 'T'?

I was speeding and ran through a stop sign, yet two traffic officers who were there do nothing about it.

why?

Why did Navjot Singh Sidhu put the new January calendar in the freezer