When I get multiplied by any number, the sum of the figures in the product is always me. What am I?

There was a competition where the contestants had to hold something. At the end of the event, the winner was a person who had no hands or feet. What was it that the contestants had to hold?

Find the missing number in the sequence below:

I live in a bowl. I can swim. I have a tail. I also have fins and big eyes. What am I?

I never was there, I am always to be.
You have never ever seen me, not ever you will.
Yet I am the confidence of everyone.

Who Am I?

I am a white box having no key or lid.
Yet there is a golden treasure inside it.

What Am I?

What goes up but never comes down?

John was a very careless driver, so his owner Jacob gave him an offer that he will get an incentive of Rs.30 for every bottle box he delivered without breaking it and he will be charged Rs.90 for every bottle box he broke. Jacob gave John 100 bottles-box to deliver. After delivery, Jacob paid John Rs.2400. How many bottles-box did John break?

A quarter is one-fourth of a dollar but Mr. John has changed the equation as below :

DOLLAR * 4 = QUARTER

Can you replace each letter with a digit to make the above solution correct?

Find the Odd One Out?
84129
32418
47632
36119
67626
72927