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?

What's the best place to go shopping in the ocean?

I have a mouth but I don't eat.
I have a bank but have no money.
I have a bed but i dont sleep.
I wave but have no hands.

Who Am I ?

A famous swimmer can swim downstream in a lake in exactly 40 minutes with the lake current.
He can swim upstream in that lake in exactly 60 minutes against the lake current.
The length of the lake is 2 km.

How long he can cover the distance of one side at a still lake with no current?

Can you find out the smallest number that can be conveyed as the sum of three squares in three unique ways?

What you cannot hold but it is yours?

Count the squares in the matchstick puzzle below?

The below given figure comprises of a pattern through which you can determine the missing letter. Can you push your mind to find the pattern and add the missing letter?

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?

Find the Next Number in the Sequence

2 9 3 1 8 4 3 6 5 7 ?