A French riddle for children illustrates the idWed, 02/12/2014 - 23:57

Parables about Volunteers and Volunteering

A French riddle for children illustrates the idea of  "exponential growth". I like to use this riddle to combat the myth that "there's plenty of time to act--I'll volunteer next year." Suppose you own a pond on which a water lily is growing. The lily plant doubles in size each day. If the plant were allowed to grow unchecked, it would completely cover the pond in 30 days, choking off all other forms of life in the water. For a long time the lily plant seems small, so you decide no to worry about it until it covers half the pond. On what day will that be? On the twenty-ninth day. You have just one day to act to save your pond.

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