a frog is at the bottom of a 30 meter well. each day he summons enough energy for one 3 meter leap up the well. exhausted, he the hangs there for the rest of the day. at night, while he is asleep, he slips 2 meters backwards. how many days does it take him to escape the well?

note: assume after the first leap that his hind legs are exactly 3 meters up the well. his hind legs must clear the well for him to escape.