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Sunday Times Teaser 2947 – 55 Divisions

by Tom Wills-Sandford

Published March 17 2019 (link)

To mark her 55th birthday, Martha, a school teacher, gave each of her nine pupils a sheet of paper with a single different digit from 1 to 9 written on it.

They stood at the front of the classroom in a row and the 9-digit number on display was divisible by 55. Martha then asked the first 3 in the row (from the left) to sit down. The remaining 6-digit number was also divisible by 55. The next 3 then sat down and the remaining 3-digit number was also divisible by 55.

The 9 digit number was the smallest possible. What was it?

6 Comments Leave one →
  1. Brian Gladman permalink

    • Erling Torkildsen permalink

      Thanks Brian

      My ambition was to engage Python’s new data types such as ‘lists’ and ‘sets’ rather than use traditional arrays. Apart from traces left from struggling with the different types of data and their methods and functions and thereby unnecessary conversions from one to the other, I feel that I started out well, but in the latter part fell back to relaying on extremely inefficient loops.

      I am prepared to upload my script, but don’t know quite how to do it..

      • Brian Gladman permalink

        Hi Erling, The way to upload Python programs is explained on the about page above.

  2. Erling Torkildsen permalink

    • Brian Gladman permalink

      HI Erling, I hope you don’t mind but I have adjusted it a bit so that it fits between the margins without scrolling.

  3. GeoffR permalink

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