Question

A snail is at the bottom of a 30-foot well. each day he climbs up three feet, but at night he slips back two feet. how many days will it take him to climb out of the well?

Answer 1

depth of the well=30 feet
length the snail ascends during day = 3 feet
length it descends at night = 2 feet
therefore, the equivalent length it covers at the end of the day=(3-2)feet = 1 feet
So, After 27 days it will cover: 27 feet
Then, the next day it will cover : (27+3) feet = 30 feet
Therefore, the snail takes (27+1)days i.e. 28 days to climb out of the well.......