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?

I have a sore throat and a severe headache. I have four tablets with me that are identical to each other and they do not have any cover on them. There is no way I can identify which tablet serves what purpose. The only thing that I know is that two of these four tablets are for the throat and the remaining two are for the headache. To treat my condition, I must take 1 of each. What will I do now?

A lion and its tamer are standing inside a cage that measures 1 unit in radius. Both of them can effortlessly run at the speed of 1 unit maximum.

1) Suppose the lion is hungry, will he be able to eat up the tamer?
2) If yes, how long can the tamer survive?

Keyboard words are not in alphabetical order, Why?

I cry without having a voice.
I fly without having wings.
I bite without having teeth.
I whisper without a mouth.

Who am I?

I am the one who remains awake when you sleep. But I need to rest when you awake. Who Am I?

2, 3, 5, 9, 17, _ What is the next number in the sequence?

No one wants to have it, but if one got it, he does not want to lose it. What is It?

Irene killed hundreds of people mercilessly and yet the police were not able to put her behind the bars. Why?

A seven-year-old kid challenged his classmates that he can make the number one disappear by adding something to it.

How can he do that?