How can you make the following equation true by drawing only one straight line: 5+5+5=550 ?

If your uncle’s sister is not your aunt, what relation is she to you?

Usually, a boxing match consists of twelve rounds. In a particular friendly match between two heavyweights, the match was finished in the ninth round itself as one of the boxers knocked out the other one.

But, in that fight, no man threw even a single punch.

How can this be possible?

10 people came into a hotel with 9 rooms and each guest wanted his own room. The bellboy solved this problem.
He asked the tenth guest to wait for a little with the first guest in room number 1. So in the first room, there were two people. The bellboy took the third guest to room number 2, the fourth to number 3, ..., and the ninth guest to room number 8. Then he returned to room number 1 and took the tenth guest to room number 9, still vacant.
How can everybody have his own room?

I sleep during the day and fly at night, but I have no feathers to aid my flight. What am I?

I am a five-letter word under you,
Remove the first letter and I am above you,
Remove the second as well and I am around you.

Who am I?

There are three boxes. One is labeled "APPLES" another is labeled "ORANGES". The last one is labeled "APPLES AND ORANGES". You know that each is labeled incorrectly. You may ask me to pick one fruit from one box which you choose.

How can you label the boxes correctly?

Always in you, Sometimes on you;

If I surround you, I can kill you.

What am I?

I’m tall when I’m young, and I’m short when I’m old. What am I?

A word I know,
Six letters contain,
Subtract just one,
And twelve is what remains.