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?