Enigma 534: Under and over
13 January 2020
Posted by on
From New Scientist #1686, 14th October 1989 [link]
The important C.A.R. Rally has just been held at Bun’s Hutch, where the track is as in the map.
There were 12 cars in the rally, numbered 1 to 12. For the start at 10:00, the cars took up the 12 lettered positions on the map, one car to each position. At 10:01 the cars all reached their first bridge, going under or over; at 10:02 the cars all reached their second bridge.
I had taken a photo at 10:01 and also at 10:02. Each photo showed all the numbers of the cars and so each bridge showed a fraction with one number over another. On one photo the fractions worked out to be 1/2, 2/3, 2/3, 2 1/3, 4, 5 1/2, and on the other 2, 2, 2, 3, 5 1/2, 7, but I forget which photo was which.
Which cars started at each of the 12 letters?