What is the fewest number of coins that would be required in order to make sure each and every coin touches exactly three other coins?

Out of four images which one is the odd one out?

A rain drop fell from one leaf to another leaf and lost 1/4th of its volume. It then fell to another leaf and lost 1/5th of the volume. It again fell on another leaf and lost 1/5th of the volume.



This process kept repeating till it fell on the last leaf losing 1/75th of its volume.



Can you calculate the total percentage of loss from the initial volume when the drop has fallen to the last leaf accurate up to two decimal places?

We can be boring,Or interesting.
We can be long,Or short.
We can have pictures,Or just words.
Many love us,But many also hate us.
What are we?

What is in seasons, seconds, centuries and minutes but not in decades, years or days?

It is deaf, Dumb and Blind!!!

Still, always tells the truth. What is it?

using four eights (8) and a one (1) and one mathematical symbol , create the number 100

The more you take me, the more you leave me behind.
Who Am I?

What number when divided in half becomes zero?

Can you place three balls such that the equation shown in the picture holds true?