I never was there, I am always to be.
You have never ever seen me, not ever you will.
Yet I am the confidence of everyone.

Who Am I?

In the picture given below, can you find out which digit will take place of the question mark?

This is a famous paradox which has caused a great deal of argument and disbelief from many who cannot accept the correct answer. Four balls are placed in a hat. One is white, one is blue and the other two are red. The bag is shaken and someone draws two balls from the hat. He looks at the two balls and announces that at least one of them is red. What are the chances that the other ball he has drawn out is also red?

2, 3, 5, 9, 17, _ What is the next number in the sequence?

What is the next number in this matchsticks series riddle?

The first box has two white balls. The second box has two black balls. The third box has a white and a black ball.

Boxes are labeled but all labels are wrong!

You are allowed to open one box, pick one ball at random, see its colour and put it back into the box, without seeing the colour of the other ball.

How many such operations are necessary to correctly label the boxes?

Different lights make me strange by changing me into different sizes. What am I?

Andrew’s doctor gives him three pills and tells him to take one every half hour. How much time will have passed by the time Andrew’s taken all three pills?

There was an aeroplane crash, every single person died, but two people survived. How is this possible?

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?