If eleven plus two equals one, what does nine plus five equal?

I am weightless, but you can see me. Put me in a bucket, and I'll make it lighter. What am I?

I am a type of food that is often found in the fridge and can be white in colour. What I am?
Hint 1: I am a dairy product.
Hint 2: You can spread me on the bread.

What can run but never walk, have a mouth that never speaks, have a head that never weeps, and have a bed but never sleeps?

I make two people out of one. What am I?

It is an eleven letter word.
The first, second, third and fourth letters form a banquet's name.
The fifth, sixth and seventh letters form a car's name.
The eighth, ninth, tenth and eleventh letters form a mode of transport.

Can you identify what word it is?

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

What is more useful when it is broken?

I have no life, but I can die. What am I?