What has 13 hearts but no other organs?

Why do we preferably have round manhole covers and not square ones?

The Little ant seems to be always confused. Do you know why?

How will you measure 15 minutes using two hourglasses of 7 minutes and 11 minutes respectively?

You are given four tennis balls and asked to arrange those balls in a manner that the distance between each one of them is exactly equal. How will you do it?

Can you spot the man between the coffee bean in the picture below ?

Look at the below sequence of letters and tell us what the next letter should be:

O T T F F S S ?

When a clock is observed, the hour hand is at a minute mark and the minutes hand is six minutes ahead of it.

When the clock is observed again after some time, the hour hand is precisely on a different minute mark and the minute hand is seven minutes ahead of it.

Can you calculate how much time has elapsed between the two observations?

People put me on the table and cut me but do not eat me. What am I?

My friends called me Iron59 because my parents are a chemist and a mathematician. What is my real name?