Question: Both G and H were sources to:
Explanation:
A, D and G each one has only one wrong answer and no blank answers.
∴ They must have obtained the key from the mastermind directly.
∴ A introduced 46 as the wrong answer, D introduced 17 as the wrong answer and G introduced 25 as the wrong answer.
H and E must have obtained the key from A as they got 46 as the wrong answer.
∴ H further introduced 92 as the wrong answer and E introduced 90 as the wrong answer.
F must have obtained the key from H and E and found that answers 92 and 90 did not match. He left these blank and introduced 14 as the wrong answer in addition to 46 (which was the same answer though wrong) for H and E.
I must have obtained the key from D and E. Answers 17, 46, 90 didn’t match and he left these as blank. He also introduced 27 as the wrong answer.
C must have obtained the key from I and introduced 56 as the wrong answer.
B must have obtained the key from E and G. Answers 25, 46, 90 didn’t match and he left these blank. He also marked 96 as the wrong answer.
∴ Combining all the above diagrams we get:
From the flow chart above it is clear that, G and H were not the sources to anyone.
Hence, option (d).
Alternatively,
G got question number 25 wrong and none of the other nine people got the same question number wrong.
∴ G and H were sources to none of the nine.