If 1+9+8=1, what is 2+8+9?

What can you hold in your right hand, but never in your left hand?

What 8 letter word can have a letter taken away and it still makes a word. Take another letter away and it still makes a word. Keep on doing that until you have one letter left. What is the word?

Take 9 from 6, 10 from 9, 50 from 40, and leave 6.

How Come ??

Two prisoners Jack and Jill are locked in a cell.
There is open window approx 40 feet above the ground of the cell.
They are never able to reach there.

Then they plan to escape by a tunnel and they start digging out.
After digging for more than 20 days, Jill comes with the different plan and they escaped.

what was the plan ?

The more of this there is, the less you see. What is it?

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

I sleep during the day and fly at night, but I have no feathers to aid my flight. What am I?

A word I know,
Six letters contain,
Subtract just one,
And twelve is what remains.

I add 5 to 9 and get 2. The answer is correct, so what am I?