Lilypad and the pond
Number Theory
Level
pending
In a pond, there is a lily pad that doubles its size every day. On the 28th day, the lily pad covered the whole pond, in what day does the lily pad covered only half of the pond?
The answer is 27.
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1 solution
The answer is 27 because the lily pad doubles its size every day and it covered the whole pond in the 28th day, so if you think about it, the opposite of double is half, so if you reverse it, it takes 1 day to half the size of the lily pad so get the half of a whole and its half, so it took 1 day to make the lily pad covering the whole pond to make the lily pad cover only half the pond, so 28 - 1 = 27.