When can we add 2 to 11 and get 1 as the correct answer?

Find The Next Number in this series.
1, 2, 6, 42, 1806 ?

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.'

Do You See It?

Which is the correct shadow of the bird?

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

Explain?

what does the below rebus mean?

Find three whole, positive numbers that have the same answer when multiplied together as when added together.

Here is a mathematical expression that also secretly tells a movie name. What movie is that?

I am the beginning of the end, and the end of time and space. I am essential to creation, and I surround every place. What am I?