How many times in a given day, minutes and hour clock comes in a straight line ?

Cristina was born in 1888. She just had her 30th birthday today how did that happen?

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?

What can run but never walks, has a mouth but never talks, has a head but never weeps, has a bed but never sleeps?

What question can you never answer yes to?

A donkey is behind another donkey
I'm behind that second donkey
But there is a whole nation behind me

It is a murder you can describe in a word.

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?

How many letters are in the alphabet?

What goes up but never comes down?

What kind of storm is always in a rush?