Why do people go to bed?

How can you throw a ball as hard as you can and have it come back to you even if it doesn't hit anything there is nothing attached to it and no one else catches or throws it.

What seven-letter word has hundreds of letters in it?

You may enter, but you may not come in. I have space, but no room. I have keys, but open no lock. What am I?

John killed hundreds of people mercilessly and yet the police were not able to put her behind the bars. Why?

Find the next number in the following series:
6, 14, 26, 98, __?

81 x 9 = 801. What must you do to make the this equation true?

I am a type of vehicle that has two wheels and is powered by humans. What am I?
Hint 1: You can ride me for exercise.
Hint 2: I am environment-friendly.

There is a bag which have 21 blue balls and 23 red balls. You also have 22 red balls outside the bag. Randomly remove two balls from the bag. * If they are of different colors, put the blue one back in the bag. * If they are the same colour, take them out and put a red ball back in the bag. Repeat this until only one ball remains in the bag. What is the color of the sole ball left in the bag ?

There was a strange boy who was born before his father. How can this be possible?