Sunday Times Teaser 2566 – A Fulfilling Strategy
by John Owen
Published: 27 November 2011 (link)
I drove down a road with a number of petrol stations whose locations I saw on my map. I decided to check the price at the first station then fill up when I found one offering a lower price (or, failing that, the last one). Looking back, I see each price per litre was different. Overall they were consecutive whole numbers of pence plus 0.9p in each case (ie 130.9p, 131.9p, 132.9p etc, not necessarily in that order).
So I’m surprised to discover the average price was a whole number of pence per litre .
How many petrol stations were there?
 This sentence is as published but it was not what John Owen intended. His correct version was wrongly edited by a sub-editor at the Sunday Times in a way that changed its meaning. John Owen has kindly provided the correct sentence as “Therefore, I am surprised to discover that the average price I could have expected to pay using my strategy was a whole number of pence per litre”.