One absent-minded ancient philosopher forgot to wind up his only clock in the house. He had no radio, TV, telephone, internet, or any other means for telling time. So he travelled on foot to his friend's place a few miles down the straight desert road. He stayed at his friend's house for the night and when he came back home, he knew how to set his clock. How did he know?

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

If you say my name, I will no longer exist. What am I?

In the addition below, all digits have been replaced by letters. Equal letters represent equal digits and different letters represent different digits.
ABCABA
BBDCAA
ABEABB
ABDBAA
------- +
AAFGBDH
What does the complete addition look like in digits?

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

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?

Prove that the below maths equation is true.

8 + 8 = 91

What is the next number in this series?

4,12,84,3612....

What does below pictogram mean?

It comprises roots which nobody sees,
Much taller than those trees,
Up and up it goes,
Still it never grows?