What will you call your mother's brother's brother-in-law?

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.

The current time can be represented by below textual rebus.

0
=========
B.Sc
LLB

Can you tell us the current time?

I can be made.
I can be cracked.
I can be told.
I can be played.

Who am I?

On one occasion, A Boy collects 71 rupees in form of 20 paise and 25 paise. He collects a total of 324 coins.

Can you tell me how many 20-paisa and 25-paisa he got?

What does it mean?

When does a USA Potato change its nationality?

What is the coolest letter in the alphabet?

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?

There are a number of books on a shelf. If one book is the 4th from the left and 6th from the right, how many books are on the shelf?