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

Can you name three consecutive days without using the words Monday, Tuesday, Wednesday, Thursday, Friday, Saturday, or Sunday?

I look flat, but I am deep. Hidden realms I shelter. Lives I take, but the food I offer. At times I am beautiful. I can be calm, angry, and turbulent. I have no heart but offer pleasure as well as death. No man can own me, yet I encompass what all men must have. What am I?

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

John enters a small room. The Door Closes.
When the door opens, John is in a larger room.

Explain?

1 rabbit saw 9 elephants while going to the river. Every elephant saw 3 monkeys going toward the river. Each monkey had 1 parrot in each hand. How many animals are going towards the river?

Give it food and it will live; give it water and it will die.

Before Mount Everest was discovered, what was the highest mountain in the world?

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 you cannot hold but it is yours?