You are presented with three boxes. One of them has a red ball inside and the other two have a black ball inside each of them. You are asked to pick up the one with red ball and you pick one. Now, one of the other boxes is opened and it is found to have a black ball.

You are presented with a chance to change your box with the one that is left closed. Will you change your box? Why or why not?

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.

Can you make the number 24 by utilizing the numbers 1, 3, 4 and 6? You must use one number only one time and you can use mathematical operation symbols anytime anywhere.

What will be the best approach to finding all the prime numbers less than 75 that leave an odd reminder when we divide them with 5?

John was running from 40 thieves. John has got 3 gold boxes which weigh as 4kg, 2kg, and 1kg respectively. A witty man asked John to stay with him for seven days in exchange for 1kg gold per day. John needs to stay there for seven days and also do not want to give the witty man any advance. How can John pay for his seven days stay?

I have two coins.
* One of the coins is a faulty coin having a tail on both sides of it.
* The other coin is a perfect coin (heads on side and tail on other).

I blindfold myself and pick a coin and put the coin on the table. The face of the coin towards the sky is the tail.

What is the probability that another side is also tail?

How many triangles are there in the picture below?

The world's largest Thanksgiving turkey was on display at a fair. Everyone was admiring it when suddenly a woman ran up and shot the turkey and left. Everyone knew her yet nobody made any attempts to stop or report her. Why?

John replied, when asked how old he was. In 2 years he will be twice as old as he was five years ago.' How old is he ?

Can you calculate the probability of getting a sum of six when a dice is thrown twice?