Sunday Times Teaser 2578 – The Right Money
by Robin Nayler
Published: 19 February 2012 (link)
In order to conserve his change, Andrew, our local shopkeeper, likes to be given the exact money. So today I went to Andrew’s shop with a collection of coins totalling a whole number of pounds in value. I could use these coins to pay exactly any amount from one penny up to the total value of the coins. Furthermore, the number of coins equalled the number of pounds that all the coins were worth; I had chosen the minimum number of coins to have this property.
(a) How many coins did I have? (b) For which denominations did I have more than one coin of that value?