Why is it very easy to weigh a fish?

Arrange the numbers 1, 2, 3, 4, 5, 6, 7, 8 and 9 above and below the division line in a manner that the thus formed fractions equal to 1/3.

(You can use one number only once)

You need to arrange three 7 and mathematical symbols to form number 1?

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?

How many words can a pen with half refill write?

By using all numbers, i.e. 123456789 and subtraction/addition, operators number 100 can be formed in many ways.
Example: 98 + 7 + 6 - 5 - 4 - 3 + 2 - 1 = 100

But if we add a condition use of the number 32 is a must. Then there are limited solutions.
One of such solution is: 9 - 8 + 76 + 54 - 32 + 1 = 100

Can you tell me any other solution?

If an electric train is travelling south, then which way is the smoke going?

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

If you had a pizza with crust thickness 'a' and radius 'z', what's the volume of the pizza?

By removing one matchstick and adding one matchstick, can you convert the word "ZOO" to an animal name?