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?

Find the missing number in the series below

13 -21 34 -55 ? -144

What mathematical symbol can be put between 5 and 9, to get a number bigger than 5 and smaller than 9?

I am a word of 12 alphabets.

* Alphabets 12, 4, 7, 2, 5 : Eastern beast of burden
* Alphabets 1, 8, 10, 9 are street made famous by Sinclair Lewis.
* Alphabets 11, 3, 6 are past.

On whole it means a person suffering from delusions of greatness.

What Is it ?

Can you write down eight eights so that they add up to one thousand?

Can you identify the hidden rebus in the image below?

I have holes on the top and bottom. I have holes on my left and on my right. And I have holes in the middle, yet I still hold water. What am I?

Which letter of the alphabet has the most water?

10+10 and 11+11 can give you the same answer.

Explain how?

I am a seven-letter word but if you remove four of my letters I will have one left. What word am I?