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?

There is a box full of marbles,
all but two are blue,
all but two are green,
and all but two are red.

How many marbles are in the box?

What has to be broken before you can use it?

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

Jenifer and Jesica are having a conversation.

Jenifer: I am definitely not over 30.
Jesica: I am 28 and you are surely 5 years older to me at least.
Jenifer: No, you are at least 29.

You are told that both of them are lying throughout in the conversation. Can you find their respective ages?

How can you spell "White of an egg" in one word?
Hint: I know you can spell coke, poke, and joke.

Here is a mathematical expression that also secretly tells a movie name. What movie is that?

What has six faces, but does not wear makeup, has twenty-one eyes, but cannot see?

If a wheel has 54 spokes, how many spaces are there between the spokes?

An express train takes 3 seconds to enter the tunnel which is 1 km long.
If it is travelling at 120 km an hour, how long will it take to pass completely through the tunnel?