There are seven Ladies Who Lunch who meet in The Jolly Quizmaster and they are always seated at the large round table on (of course) seven chairs. The ladies are named Alice, Belinda, Clare, Denise, Evie, Fiona and Grace.
In order that all the ladies have a chance to converse with all the other ladies they have a rule that no one can have the same neighbours on more than one occasion during a calendar month.
For example, should they sit in the order listed in the first paragraph, with Denise seated next to Clare and Evie, then Denise cannot sit next to either of them again that month.
Now these ladies are very keen on socialising and will meet for lunch as often as they can. So the question is, how many times each month are they able to take lunch whilst observing the rule about neighbours.
At first sight it would appear that there will be many combinations that will comply with the rule, and allow the Ladies Who Lunch to meet many times each month. Sadly for them this is not the case.
Take Denise as an example. There are six other ladies who can be put into three pairs, and once she has sat by these three pairs there are no more ladies who she can sit by. Until the following month.