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.

What demands an answer, but asks no questions

Find the next number in the series?
2, 12, 36, 80, 150, 252, 392, _ ?

Three ants are sitting at the three corners of an equilateral triangle. Each ant starts randomly picks a direction and starts to move along the edge of the triangle. What is the probability that none of the ants collide?

A famous swimmer can swim downstream in a lake in exactly 40 minutes with the lake current.
He can swim upstream in that lake in exactly 60 minutes against the lake current.
The length of the lake is 2 km.

How long he can cover the distance of one side at a still lake with no current?

You have a square. What you have to do is cut and reassemble the square such that you create a Red Cross sign that has the same volume as that of the square.

There's one "sport" in which neither the spectators nor the participants know the score or the leader until the contest ends.

What is it?

A blonde put eyeliner on her head. Why?

Can you find the largest Three-digit number whose sum is 14 and whose square is less than 5,00,000?

I am never scared but became petrified and can’t live in a house but would die to make one. What am I?