I speak without a mouth, and hear without ears. I have no-body, but I come alive with the wind. What am I?

Your job is to measure 45 minutes if you have only two cords and matches to light the cords.

1. The two cords are twisted from various materials, so their different segments can burn at different rates.
2. Each cord burns from end to end in exactly one hour.

Describe your way of measuring the 45 minutes.

At my favorite fruit stand,
an orange costs 18,
a pineapple costs 27,
and a grape costs 15.
Using the same logic, can you tell how much a mango costs?

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 am beautiful, up in the sky. I am magical, yet I cannot fly. To people I bring luck, and to some people, riches. The boy at my end does whatever he wishes. What am I?

I am white when I am dirty, and black when I am clean. What am I?

In the given figure, you can see that four match sticks are used to form a square. Can you form five squares by using six matches?

Take away my first letter, then take away my second letter. Then take away the rest of my letters, yet I remain the same. What am I?

What is the riddle which can be asked all day with a different correct answer each time.

You see me once in June, twice in November, and not at all in May. What am I?