A snail rests at the bottom of a 30-foot deep dry well. Every morning it climbs up 3 feet, but every night it slides backward 2 feet while resting. On which day does the snail crawl out of the top?
Day 28
The snail achieves a net gain of 1 foot each full 24-hour cycle. By the end of night 27, it sits at 27 feet. On the morning of Day 28, it climbs 3 feet to reach 30 feet and exits before sliding back.
About this riddle
Math riddles hide a calculation inside a short story. Pull out the numbers, work out what is being asked, and watch for a trick such as a unit change.
Difficulty: Medium. More like this: Math riddles with answers or try Target 24 for a different kind of puzzle.
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