What does this simple rebus mean?

Which Burger Is Different in below image?

Here is what you have to do. You have to throw a ball as hard as you can but it must return back to you even if it does not bounce at anything. Also, you have nothing attached to the ball. There is no one on the other end to catch that ball and throw it back at you.

How will you do it?

Which is faster, Heat or Cold ? Explain.

Can you write down eight eights so that they add up to one thousand?

Find the last number in the series below:

voN luJ yaM raM ---

A mother is 21 years older than her child. In exactly 6 years from now, the mother will be exactly 5 times as old as the child.
Where's the father?

I am under you when I am whole.
I shift above you if you remove the first letter.
I come all around you if you remove the second as well.

Can you tell me who I am?

Find the mistake in the below maths equations

A = 2
A(A-1) = 2(A-1)
A2-A = 2A-2
A2-2A = A-2
A(A-2) = A-2
A = 1

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