Our product and our sum always give the same answer. Who are we?

A pond had 60 fish, out of which, all but 20 died.
How many fishes are now present in that pond?

A man was found murdered on Sunday morning. His wife immediately called the police. The police questioned the wife and staff and got these alibis: The Wife said she was sleeping. The Cook was cooking breakfast. The Gardener was picking vegetables. The Maid was getting the mail. The Butler was cleaning the closet. The police instantly arrested the murderer. Who did it and how did they know?

You are given four tennis balls and asked to arrange those balls in a manner that the distance between each one of them is exactly equal. How will you do it?

I have Rs.50 and I spend it in the way as below.

what does this picture(rebus) riddle means ?

It belongs to you, but other people use it more than you do. What is it?

John is asked to stand behind Jacob and Jacob is asked to stand behind John. Both of them feel confused about it and don't know what to do?

But it is quite possible, do you know how?

John named his first son Alpha, second Beta, third Charlie and fourth Delta. What is the fifth son's name?

Can you spot what's wrong with the following sentence?

PETER WAS ANGRY AT
HIMSELF BECAUSE HE
ACCIDENTALLY LEFT THE
THE KEYS TO HIS CAR
AT HIS FRIEND'S HOUSE.