Can you identify the hidden rebus in the image below?

P is the father of Q and S is the son of R. T is the brother of P and has a daughter U. If R is the sister of P, then what is the relation between U, Q and S?

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

What does the below mathematical rebus mean?

Rearrange the letters in "new door" to make one word.

What goes up but never comes down?

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?

What has a bottom at the top?

A finger goes in me. You fiddle with me when you're bored. The best man always has me first. What am I?

What does this mathematical rebus means ?