A snail falls into a well 5 feet deep, how many days will it go out if it advances two feet in the day and comes back one meter at night?
4 days
Day 1: 2 -1 = 1
Day 2: 1 +2 -1 = 2
Day 3: 2 + 2 - 1 = 3
Day 4: 3 +2 = 5.
4 days
Day 1: 2 -1 = 1
Day 2: 1 +2 -1 = 2
Day 3: 2 + 2 - 1 = 3
Day 4: 3 +2 = 5.