Give it food and it will live; give it water and it will die.

I am a type of vehicle that has two wheels and is powered by humans. What am I?
Hint 1: You can ride me for exercise.
Hint 2: I am environment-friendly.

Find a 9-digit number, which you will gradually round off starting with units, then tenth, hundred etc., until you get to the last numeral, which you do not round off. The rounding alternates (up, down, up ...). After rounding off 8 times, the final number is 500000000. The original number is commensurable by 6 and 7, all the numbers from 1 to 9 are used, and after rounding four times the sum of the not rounded numerals equals 24.

Replace each alphabet with the number (1-9) to make the below equation correct.

AB * C = DE - F = GH / I

What has no start, end, or centre?

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

Do you know of a place where the wind blows south and then suddenly shifts direction towards the north?

Replace the question mark with the correct number.

If an earthquake is 1 point higher on the Richter Scale than another earthquake which is actually 10 times stronger, how much stronger would an earthquake be if it was just half a point higher on the Richter scale?

What 5-letter word typed in all capital letters can be read the same upside down?