IBM Ponder This #016 · August 1999

At every meal, $M+N$ people are seated at two separate tables: one with $M$ seats and one with $N$ seats. To “sit with” someone means to sit at the same table, not necessarily next to them.

How many meals are needed so that every person sits with every other person at least once?

At a given meal, everyone occupies one seat throughout the meal and the tables do not overlap.

Solution

Best opened after a real attempt

Solution

To be added.