When my father was 31 I was 8. Now he is twice as old as me. How old am I?

A man has a barrel filled with oil that weighs 100 pounds, and then he puts something into it. Now the barrel weighs less than 100 pounds. What did he put in the barrel?

Look at the picture and find out which square is not linked with any of the other squares.

Identify the next two numbers in this series.

101, 112, 131, 415, 161, 718, ???, ???

Imagine a box with two cogwheels, one big with 24 teeth and one small with 8 teeth. The big one is firmly attached to the center of the box which means it does not turn or move while the small one rotates around the big one.

How many times do you think that the smaller wheel will turn compared to the box when it turns once around the big one?

Buy me, smell me or deliver me, I do not change.

Who am I?

Three doctors said that Bill was their brother. Bill says he has no brothers. How many brothers does Bill actually have?

Solve the following series:
AZ, GT, MN, __, YB

If you remove one from eleven, it becomes ten. If you remove one from nine, it becomes ten.

How is this possible?

Rebus Puzzle Definition: A rebus is an illusion device that uses pictures to represent words or parts of words.
What does This Rebus Puzzle Identify?