O_er_t_o_

Complete the missing letters of the given word.

What jumps when it walks and sits when it stands?

How can you write nineteen in a manner that if we take out one, it becomes twenty?

I am a type of food that is often found in the fridge and can be white in colour. What I am?
Hint 1: I am a dairy product.
Hint 2: You can spread me on the bread.

The dirtier I get, the whiter I look. Who am I?

They came out at night, without being called.
They lost at day, without being stolen.
Who are they?

I hide my treasure in the ground, my tail is big and fluffy. If you spot me in a tree, please don’t call me scruffy. 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 a normal creature, but I have five hands. I can even have more but even then I will be considered normal.

Who am I?

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