Questo problema è tratto dalla collezione "The problems of the All-Soviet-Union mathematical competitions 1961-1986", nella versione inglese di Vladimir A. Pertsel. In particolare, il problema è stato assegnato alla "11-th competition -- Tallinn, 1977".
Seven elves are sitting at a round table. Each elf has a cup. Some cups are filled with some milk. Each elf in turn and clockwise divides all his milk between six other cups. After the seventh has done this, every cup was containing the initial amount of milk.
How much milk did every cup contain, if there was three litres of milk total?
Rispondete in italiano o in inglese, come vi pare.
Buona settimana a tutti       wm