A water lily in a pond doubles in size every day. If it takes 48 days for the lily to completely cover the pond, on which day was the pond exactly half-covered?
Day 47
Since the lily doubles in size every day, working backward one day from day 48 (100% full) gives day 47 (50% full).
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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