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?

Quickly Solve this riddle

7 - 4 + 3 * 0 + 1 = ?

I am quite hot but become too cold if you remove the first two letters. What am I?

What does this mean?

CCCCCCC

They came out at night, without being called.
They lost at day, without being stolen.
Who are they?

How many pluses should we put between the digits of 987654321 to get a total of 99, and where?

Count the squares in the matchstick puzzle below?

When I got four, I have it none.
When I got two, I have it some.
When I got none, I have it all.

What is it?

What have one eye but still cannot see?

I came first on earth but second on the heaven.
I also came twice in a week but found just once in a year.
I stay away from months but you can find me in February.

What am I?