Can you solve the tricky chess rebus puzzle below by ciphering the hidden meaning?

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 sure no one can have two things for dinner. what are they?

If 5 cats catch 5 mice in 5 minutes, how long will it take one cat to catch a mouse?

A newspaper is supposed to have 60 pages, but pages 24 and 41 are missing.
Which other pages won't be there?

Which three-digit number, made of consecutive digits, like 567, is 2 less than a cube and 2 more than a square?

The square root of number 121 is "11". What is the square root of the number "12345678987654321."?

Known by all without exception, Forever here, for your protection, Sometimes strong, sometimes weak, Right after the night I come - hot and chic. And while millions of miles away, I always get to you, I find my way. No life around could do without me, Can you guess what I might be?

In an interview, a boy was asked an unusual question 'How two persons sitting with a table in between them can't see each other?' He was unable to reply. Can you?

Who can jump higher than a Mountain?