A Scientist was fifty years old in the year 2000 but he was forty years old in the year 2010. How can this be possible?

PS: It has a logical answer.

A mother is 21 years older than her child. In exactly 6 years from now, the mother will be exactly 5 times as old as the child.
Where's the father?

Find the missing number in the image below.

There is something which you can be arrested for attempting but not for successfully completing.

I travel all around the world but always stay in the corner. What am I?

Can you solve the rebus below?

Here is a Swiss Cross. You have to make two straight cuts in the figure so that it is divided into four congruent pieces. Also, you should be able to join these pieces into a square then. Can you accept this challenge?

I have a hole in my back and legs I lack.
I live where I can’t breathe and I eat without teeth.
What am I?

You have three orange, two pink and five purple balls in the drawer beside your bed. There is no electricity and the room is entirely dark. How many balls must you take out to ensure at least one ball of each colour at least?

What does this rebus mean?

O
N
C
E
TIME