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

The Puzzle: A girl, a boy, and a dog start walking down a road.

They start at the same time, from the same point, in the same direction.

The boy walks at 5 km/h, the girl at 6 km/h.

The dog runs from boy to girl and back again with a constant speed of 10 km/h. The dog does not slow down on the turn.
How far does the dog travel in 1 hour?

Why 1729 is a magic number? Answer Logically.

A man started to town with a fox, a goose, and a sack of corn. He came to a stream which he had to cross in a tiny boat. He could only take one across at a time. He could not leave the fox alone with the goose or the goose alone with the corn. How did he get them all safely over the stream?

I sleep during the day and fly at night, but I have no feathers to aid my flight. What am I?

Begin with a word, five letters to my name,
Remove the first and last but I am the same
Take out my middle and still, I remain.
What word am I?

Two in a corner, one in a room, zero in a house, but one in a shelter. What is it?

I am looking for a word that change both gender and number when i add the letter 'S'.

What Word am I Looking For ?

I am a seven-letter word but if you remove four of my letters I will have one left. What word am I?

I am a normal creature, but I have five hands. I can even have more but even then I will be considered normal.

Who am I?