Two guards were on duty outside a barracks. One faced up the road to watch for anyone approaching from the North. The other looked down the road to see if anyone approached from the South. Suddenly one of them said to the other, "Why are you smiling?"

How did he know his companion was smiling?

What can you see in the middle of March and April that you can never see in any other month?

Can you count the number of children in the picture below

I can sizzle like bacon,
I am made with an egg,
I have plenty of backbone, but lack a good leg,
I peel layers like onions, but still remain whole,
I can be long, like a flagpole, yet fit in a hole.

Can you count the number of triangles inside a triangle?

The horse jumps over the king.
Strangely there is absolutely no scratch on him.

Can anyone explain, how is this possible?

It's a protector.
It sits on a bridge.
One individual can see directly through it, while others wonder what it hides.

What is it?

There is one four-digit whole number n, such that the last four digits of n2 are the original number n

Can you count the number of squares in the figure below?

This puzzle is for Harry Potter fans. Do you know why Tom Riddle is called Lord Voldemort?