Four cards on the table have a number on one side and a letter on the other.
Rule: "If a card has D on one side then it has a 3 on the other side."
Which card(s) do you have to turn over to verify whether the rule is true?
Rule: "If a card has D on one side then it has a 3 on the other side."
Which card(s) do you have to turn over to verify whether the rule is true?
The four cards show,
>D
>F
>3
>7
The third best answer is D and 3, but it is wrong. The statement in question states, "if D then 3" No matter what is on the other side of the 3, it doesn't tell us anything about what D requires.
>F
>3
>7
The third best answer is D and 3, but it is wrong. The statement in question states, "if D then 3" No matter what is on the other side of the 3, it doesn't tell us anything about what D requires.
The second best answer is just D, but it is also wrong. It is true that you need to flip over D to find out if it has a 3 on the other side. But you also need to flip another card to see if D necessitates 3.
The correct answer is D and 7. You have to flip over D to find out if 3 is on the other side, but you also need to flip over 7 to see if there is a D on the other side. If there is then the rule is false.
The correct answer is D and 7. You have to flip over D to find out if 3 is on the other side, but you also need to flip over 7 to see if there is a D on the other side. If there is then the rule is false.
This is an example psychologists give for human failure at deductive reasoning.
