I'm new to this

I've seen puzzles in newspapers asking us to force mate in specific number of moves. There what will be the moves of the other side? 

Normally they will be forced e.g. the king only has one square to move to, they have to recapture to get out of check etc.

the site sure does

thnx for the answers

I should say, if it's a mate in 2, they expect you to be able to mate in 2 to every legal reply.

While using analysis board(in online chess) is it possible for the oppponent to see our analysis if he/she is online at the time we do our analysis ? 

No,only you.

Can a member without premium membership join another tournament when he is eleminated from a tournament but that tournament has not been completed ?