DAY 250
A snail starts at the bottom of a well 16 feet deep and crawls up 4 feet each day. Each night it slips back 3 feet. How long will it take the snail to reach the top of the well?

Answer:

13 days..............After 12 days it has climbed 12 feet. On the 13th day it climbs 4 feet and reaches the top.