A snail is at the bottom of a 20 meters deep pit. Every day the snail climbs 5 meters upwards, but at night, it slides 4 meters back downwards. How many days does it take before the snail reaches the top of the pit?

+3 votes

A snail is at the bottom of a 20 meters deep pit. Every day the snail climbs 5 meters upwards, but at night, it slides 4 meters back downwards. How many days does it take before the snail reaches the top of the pit?

...