It's almost Halloween at Farthingbottom School and Professor Charles Flavanna is getting festive.
"Right children, put down your copies of The Origins of Fort Monmouth - it's time to carve some pumpkins! Have a look at my creation and follow suit. You have 30 minutes and no talking."
After a sterling effort by the class, the following pumpkins were produced:
"Hold on a minute", said the Professor, "two of you have not been paying attention."
Question: Which children have made a mistake and what should their pumpkins have looked like?