Figure 1.

Story Paragraph 1

Teenagers who do not have their own cars usually end up borrowing their parents' cars. In return for the privilege of borrowing the car, the Goldstein's have given their kids the rule: “If you borrow the car, then you have to fill up the tank with gas.”

You want to check whether any of the Goldstein teenagers ever cheat on this rule.

Story Paragraph 2

You will see cards representing some of the Goldstein teenagers. Each card represents one teenager. One side of the card tells whether or not that teenager borrowed the car on a particular day, and the other side tells whether or not that teenager filled up the tank with gas that day.

You are concerned that some of these teenagers may have cheated.

Story Paragraph 3

As you see each card, tell us if you would definitely need to turn over that card to find out if that teenager has violated the rule:

“If you borrow the car, then you have to fill up the tank with gas.”

Don't turn over any more cards than are absolutely necessary.