A snail starts climbing up a slick 20-foot vertical wall. Every single day, the snail climbs up 4 feet, but every single night while sleeping, it slips back 3 feet. On which exact day will the snail first reach the top of the wall?
Day 17
On each of the first 16 days, the snail net gains 1 foot per 24-hour cycle (4 up, 3 down), reaching 16 feet high by the end of Day 16. On Day 17, it climbs the remaining 4 feet straight to the top during the daytime, before any slip can occur.
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: Medium. More like this: Logic riddles with answers or try Einstein's Logic Grid for a different kind of puzzle.
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