In four steps you need to move the word 'cold' From 'warm' by replacing one alphabet at a time such that every word formed at each step is acceptable in English Dictionary.

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

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.

Three ants are going up a hill, one behind the other. The last ant then says to the other ants, 'There is an ant behind me!'' How come?

What has six faces, but does not wear makeup, has twenty-one eyes, but cannot see?

If I remove one from eleven it becomes Ten and if I remove one from nine also becomes Ten. How?

How can you take 2 from 5 and leave 4?

I have four wings but can't fly.
I express no emotions.
I am found on the exact spot every time you look.
I keep toiling away with a little sound.

Do you know what am I?

What have one eye but still cannot see?

How many letters are in the alphabet?