Well done to Billie-Jo Allen (Age 11, Tattingstone School, UK), Rowena Scott, Charlote Ibbetson & Ross Garside (Stockton) and Timothy, Vincent & Kenneth (Catholic High School, Singapore) for correct solutions. Four particularly well presented graphic solutions came from Chris Hannay, Michael Hemmingway (& name missing) from Crofton Junior School, and Daniel Loh (Age 10, Anglo-Chinese School, Singapore).

This one comes from Rayner Teo (Year 5, Tao Nan School, Singapore)

Five rows this way Five rows this way and two more this way

5 + 5 + 2 = 12 rows