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?

How many letters are in the alphabet?

You are on a Boat in the mid of a river. You have two cigarettes with you. One of these two you have to light, how will you light the cigarette?

A word I know,
Six letters contain,
Subtract just one,
And twelve is what remains.

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

Count the number of triangles in the given picture.

Two fathers and two sons went fishing one day. They were there the whole day and only caught 3 fish. One father said, that is enough for all of us, we will have one each. How can this be possible?

Count the number of lines in the image below ?

A man says, "Brothers and sisters, have I none, but that man's father is my father's son." Who is that man?