The coins currently in circulation in Britain are for 1p, 2p, 5p, 10p, 20p, 50p, 100p and 200p. When I gave one of each of these coins to Tom and Harry to share between them, each took two or more coins, with each person's coins' total value equal to a prime number of pence. No coins were left over.
I asked Harry whether his share was a specific number of coins that I mentioned. He said "no".
I then asked Harry whether he had the coin of a denomination I specified. He said "yes".
His two answers allowed me to determine the total of the value that Harry had taken. What was that value?
A Perl program gives the following eight possible sets for Harry:
# 1p 2p 5p 10p 20p 50p 100p 200p Total
3 X X X 71p
3 X X X 251p
3 X X X 107p
4 X X X X 131p <==
4 X X X X 257p
5 X X X X X 281p
5 X X X X X 137p
5 X X X X X 317p
Harry did you take five coins? No.
Harry did you take the 10p? Yes.
Harry you have a total of 131p.
Posted by Bractals
on 2005-09-17 04:19:51