Enigma 248: Add or multiply
5 January 2015
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From New Scientist #1395, 2nd February 1984 [link]
I gave each of the five boys a different amount of money, and said to each:
“Spend all this on goodies at the corner shop. Each goodie you buy must cost a different exact number of half-pennies. When you multiply together the prices (in pence) of all your purchases, the result must be the same as if you added them.”
When they came back, they had all done as I asked: each had bought the same number of goodies; and in one case each of the prices was an exact whole number of pence.
How much did my generosity cost me altogether?