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?

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 ...