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 thief enters a store and threatens the clerk, forcing her to open the safe. The clerk says, “The code for the safe is different every day, and if you hurt me you’ll never get the code.” But the thief manages to guess the code on his own. How did he do it?

What number do you get when you multiply all of the numbers on a telephone's number pad?

There are 2 people near the river and both of them want to get on the other side. The boat can only take one of them. But they got across.
How?

There was an aeroplane crash, every single person died, but two people survived. How is this possible?

I noticed one of the words in the oxford dictionary is spelled incorrectly. What about you?

"That Restaurant always remains crowded. This is the reason why nobody goes there".

Can you find a flaw in this statement?

A pond had 60 fish, out of which, all but 20 died.
How many fishes are now present in that pond?

Cristina was born in 1888. She just had her 30th birthday today how did that happen?

A boy was at a carnival and went to a booth where a man said to the boy, "If I write your exact weight on this piece of paper then you have to give me $50, but if I cannot, I will pay you $50." The boy looked around and saw no scale so he agrees, thinking no matter what the carny writes he'll just say he weighs more or less. In the end the boy ended up paying the man $50. How did the man win the bet?