A man dies of old age on his 25 birthday. How is this possible?

Imagine you are in a room with no windows or doors. How will you get out?

You want to boil a two-minute egg. If you only have a three-minute timer (hourglass), a four-minute timer and a five-minute timer, how can you boil the egg for only two minutes?

Why are all black people so quick ?

You are in a room that has three switches and a closed door. The switches control three light bulbs on the other side of the door. Once you open the door, you may never touch the switches again. How can you definitively tell which switch is connected to each of the light bulbs?

Which tank will fill first?

Why is the Hole below a Lock?

A sundial has the fewest moving parts of any timepiece. Which has the most?

Can you name an animal whose killing cannot be performed without spilling your own blood?

There are three boxes which are labeled as Rs100, Rs150, and Rs200. One box contains two notes of Rs. 50. The second box contains one note of Rs50 and one note of Rs100 The third box contains two Rs. 100 notes. All boxes are labeled incorrectly.

What is the minimum number of boxes you must check in order to label all boxes correctly?