A Problem of Water Lillies
In India water lilies grow extremely rapidly in the ponds. If the growth enlarged so much that each day it covered a surface double that which it filled the day before, so that at the end of the 20th day if entirely covered the pond, in which it grew, how long would it take two water lilies of the same size at the outset and at the same rate of growth to cover the same pond?
A Problem of Family Relations
Every man or woman alive today had 2 parents, 4 grand-parents, 8 great-grand parents, 16 great-great-grand parents, 32 great, great, great grand parents and so on.
Let us take the case of Ram. Two generations ago Ran had 2 x 2 or 22, or 4 ancestors. Three generations age he had 2 x 2 x 2 or 23or 8 ancestors. For generations ago he had 2 x 2 x 2 x 2 or 24 or 16 ancestors.
A Problem of Chain Letters
I opened my mail box this morning. What do l see in it? A chain letter. This seems to turn up every now and then in one form or another.
I began to wonder. If one person sends a certain letter to two friends, asking each of them to copy the letter and send it to two of their friends, those in turn each send two letters to two of their friends and so on how many letters would have been sent by the time the letter did thirty sets.




