Why do people go to bed?

Can you start the fire using two pieces of wood?

A network of 20 x 10 squares is given to you.

Can you calculate how many unique squares and rectangles can be formed combining two or more individual squares ?

Speaking of rivers, a man calls his dog from the opposite side of the river. The dog crosses the river without getting wet, and without using a bridge or boat. How?

Take away the whole and some still remain. What is it?

I am the beginning of everything, the end of everywhere. I'm the beginning of eternity, the end of time and space. What am I?

Solve this riddle by finding the odd one out from the rest.

In the below-given picture of a pretty girl, there is something wrong. Can you find out what it is?

There is a square piece of paper with a hole that is denoted by the circle on the top right side in the given picture. You have to cut the paper in a manner that it forms two and only two separate pieces of paper and then rearrange the pieces in a manner that the holes come in the centre of the paper.

Keyboard words are not in alphabetical order, Why?