If nothing else, people can enjoy a great song.
This one puzzled us when we gave the 2021 Further Mathematics Exams a three-minute scan, but we didn’t bother then to think, um, further. Now, however, since graph theory is likely a mandatory part of Specialist 1&2, and thus also, at least technically, a mandatory part of Specialist 3&4, we have thought a little harder. So, after discussions with John Friend and with a colleague who we shall refer to as Professor Combo, here we are.
The following question appeared in the Network module on the 2021 Further Mathematics Exam 1. Have fun.