HOW MANY DAYS WILL TAKE THE WORM TO ESCAPE FROM THE WELL?

Question

A WORM IS AT THE BOTTOM OF A 30 FOOT WELL.  EACH DAY HE SUMMONS ENOUGH ENERGY TO CRAWL 3 FEET UP THE WELL.  EXHAUSTED, HE THEN HANGS THERE FOR THE REST OF THE DAY; BUT AT NIGHT, WHILE HE IS SLEEPING, HE SLIPS 2 FEET BACK DOWN THE WELL. 

Answer 1

                    day                      night

Day 1:    from 30 to 27 feet     to 29 feet

Day 2:    from 29 to 26 feet     to 28 feet

Day 3:    from 28 to 25 feet     to 27 feet

Day 4:    from 27 to 24 feet     to 26 feet

  . . .               (see the pattern?)

Day 26:  from 5 to 2 feet        to 4 feet

Day 27:  from 4 to 1 foot        to 3 feet

Day 28:  from 3 to 0 feet ----- the worm is out !!