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

How many times can you subtract the number two from the number fifty?

I am taken from a mine and shut up in a wooden case, from which I am never released, and yet I am used by almost every person. What am I?

I am weightless, but you can see me. Put me in a bucket, and I'll make it lighter. What am I?

I am dry when I go inside, but wet when I am pulled outside.
The longer I am inside, the stronger I get
When I am completely out, I am wet and I literally sag
Who am I?

What has many keys but can’t open a single lock?

What jumps when it walks and sits when it stands?

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

Why 1729 is a magic number? Answer Logically.

How can you take 2 from 5 and leave 4?