Place the numbers from 1 to 9 in the circles in a manner that each side of the triangle sums up to 17.

A woman lives in a skyscraper thirty-six floors high and is served by several elevators which stop at each floor going up and down. Each morning she leaves her apartment and goes to one of the elevators. Whichever one she takes is three times more likely to be going up than down. Why?

A man says, "Brothers and sisters, have I none, but that man's father is my father's son." Who is that man?

The person who makes it has no need for it; the person who buys it has no use for it. The person who uses it can neither see nor feel it. What is it?

The more you take me, the more you leave me behind.
Who Am I?

Two fathers and two sons went fishing one day. They were there the whole day and only caught 3 fish. One father said, that is enough for all of us, we will have one each. How can this be possible?

Can you fill the blank with the correct number?

6 30 870 756030 _____

It is a 5 letter word if you take away first letter it is something you get from sun, if you remove second letter you will get something to eat, if you remove third letter you get a word you use in pointing at and if you remove the fourth letter you get something to drink. What is it?

What will be the best approach to finding all the prime numbers less than 75 that leave an odd reminder when we divide them with 5?

There is one four-digit whole number n, such that the last four digits of n2 are the original number n