A monkey is at the bottom of a 30 meters well. During the day he climbs 3 meters.
During the night he slides down 2 meters.
How many days does it need to get out of the well?
Why is the answer not 30?
The answer is 28 days....
On one morning, he will be able to jump to the top in one jump.
He gains one meter every day after 27 days he is at 27 meters on the 28th day he will top out at 30 meters (and he won't slide back down we assume)