Complete the table series riddle by finding the number that can replace "??".

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

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

Three doctors said that Bill was their brother. Bill says he has no brothers. How many brothers does Bill actually have?

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

In the given picture, in how many ways can you read the word "Tiger"?

Rahul decided to meet Simran so he boards a local train from Bombay station. Just after the station, there is a 1km long tunnel. The train starts and is now accelerating. Rahul is a claustrophobic guy, so what is the best position for him to sit?

You have an empty wine bottle with a cork that has been secured at the top in a normal way. There is a metal ring inside the bottle that is suspended by a string.

How can you make the metal ring drop to the bottom if you are not allowed to touch anything - not the bottle, not the cork, not the thread and not the ring?

I am the first thing you need while camping.
I am always with the person named Marcos Valencia and Carrick.
But Pogba Zlatan and Rooney think I am wasteful and do not need me.
I am the second to the last thing to add when you are making a patch.

What am I?

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