by Victor Bryant
published December 17 2017 (link)
Snow White placed three balls in a hat (“Oh yes she did!”): written on each ball was a different non-zero digit. She asked one of her little helpers to draw out the three in some order and to use them in that order to make a three-figure number. She knew that this number would be divisible by three but not by seven. She asked the helpers to share out that number of sweets equally amongst the seven of them as far as possible and to give her the remainder. On seeing the remaining sweets she was always able to work out the order in which the three digits had been drawn out.
What (in increasing order) were the three digits?