A snail climbs up a 10-meter wall. Every day it climbs 3 meters, but every night it slips back 2 meters while sleeping. On which day does the snail reach the top of the wall?
The 8th day
On each of the first 7 days, the snail makes a net progress of 1 meter per 24-hour cycle (3 up, 2 down). After 7 days, it has climbed 7 meters. On the 8th day, it climbs 3 meters during the day. Since 7 + 3 = 10, it reaches the top of the wall before nightfall, meaning it doesn't need to slip back.
About this riddle
Logic riddles give you a few facts and ask what must be true. List what you know, cross out what cannot be, and see what is left.
Difficulty: Easy. More like this: Logic riddles with answers or try Einstein's Logic Grid for a different kind of puzzle.
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