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?

Can you think of a smallest +ve number such that if we shuffle the digits of the number, the new number becomes double the original number?

An exterior architect is asked by a builder to plant seven trees in a manner that there are exactly six rows of trees in a straight line and each row has three trees in particular.

How will he do it?

It comprises roots which nobody sees,
Much taller than those trees,
Up and up it goes,
Still it never grows?

Can you replace the question mark with the correct number?

A sundial has the fewest moving parts of any timepiece. Which has the most?

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.

Replace each alphabet with the number (1-9) to make the below equation correct.

AB * C = DE - F = GH / I

I never stop running even when I standstill. If I am formed by joining two identical bodies together, can you guess who I am?

There once were seven dwarfs who were all brothers. They were all born two years apart. The youngest dwarf is seven years old. How old is his oldest brother?