Question 2
Place each of the numbers 2, 3, 4, 5, 6, 7 and 8 exactly once in the eight empty circles (the position of 1 is already fixed) such that the sum of each pair of adjacent numbers is a prime number. Diagrams are considered the same if one can be obtained from the other by reflection or rotation. List all possible diagrams.
Source wording note: “eight empty circles” is printed in the original. The diagram actually has eight circles in total, with seven empty circles and a fixed 1. The task is interpreted as filling those seven empty circles. The original blank answer diagrams are retained below.
Source wording note: “eight empty circles” is printed in the original. The diagram actually has eight circles in total, with seven empty circles and a fixed 1. The task is interpreted as filling those seven empty circles. The original blank answer diagrams are retained below.