You are an inspector for a new privatised bus company which does not sell tickets on buses. Your pay is performance related, according to how well you detect violations of the following company rule.

"IF SOMEONE HAS OUR PASS THEN THEY TRAVEL ON OUR BUS"


Each card below represents one person. One side of the card indicates whether the person is travelling on your bus, and the other whether the person has an appropriate bus pass.

Which cards do you definitely need to turn over to see if any of these people are breaking the rule? (In some recent browsers you may get feedback by clicking on the cards.)


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