The more of this there is, the less you see. What is it?

I want to fill my bucket using both cold and hot water.
I have two taps for both cold and hot water. The hot water tap fills the bucket in exact 6 hours and the cold water tap fills the bucket in exact 4 hours.
I turn both of them simultaneously but I forgot to turn off another tap which removes the water out of the bucket. This tap can empty the bucket in 12 hours.

How Long will it take to fill the bucket?

I have a head like a cat and feet like a cat, but I am not a cat. What am I?

what does this below rebus represent identXQQQQQME

I know a nine-letter word having only one vowel.
Do you ?

A large container is kept in open under the rain. Every passing hour, the water collected inside the container becomes double what it was.

In ten hours, the container is filled completely. Can you calculate how long would it have taken to be filled in half?

Below toothpicks/matchsticks indicate the group of fishes moving from west to east direction. Can you make them move from east to west by just moving three toothpicks/matchsticks?

Why do you find that most of the buildings are deprived of the 13th floor?

How can a man go eight days without sleep?

2, 3, 5, 9, 17, _ What is the next number in the sequence?