What is the Surname of Barbie Doll?

What demands an answer, but asks no questions

I am the fastest animal but cannot climb the tree. What am I?

What common phrase is represented by the below lines

Easy going:
Weak, 'I'm going.'
Tough, 'I'm staying.'

Medium going:
Weak, 'I'm going.'
Tough, 'I'm staying.'

Tough going:
Weak, 'I can't do it, I'm staying!'
Tough, 'Let's get going.'

John said, "If yesterday was tomorrow, today would be Friday."

When did John make this statement?

I know a 5-digit number having a property that With a 1 after it, it is three times as large as it would be with a one before it.

Guess the number?

You need to pick one entry from pot A and one from pot B to have a perfect match. Can you do it?

If 2 workers can complete painting 2 walls in exactly 2 hours.

How many workers would be needed to paint 18 walls in 6 hours?

f you were running a race, and you passed the person in 2nd place, what place would you be in now?

Can you solve this amazing hard number series problem?
7, 8, 10, 12, 16, 18 ?