Initially silenced by their discovery, the 40 students soon started to giggle at the mistake, and their stony-faced invigilators collected all the papers up.

The papers had the offending answers removed and were redistributed.

As quoted in the Evening Standard, a spokesman for Imperial College London said: “The Department reviewed the situation carefully and concluded that students would not have been able to use the information to any advantage during the short time they had access to part of the answer scheme.”

That’s lucky. Imagine if they’d all kept quiet? Top marks all round!

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