P. 176 Incorrect logic

[jcutts]

Question 3, at the top of the page, is not logical as it stands. It should be changed as follows. The characters in bold are the ones that change.

Change: A and B are found together. A, B, and C are also found together. Therefore, A must cause C.

To: A and B are found together. A, B, and C are also found together. Therefore, B must cause C.

Change: This eliminates B as a cause of C and strengthens A as the cause.

To: This eliminates A as a cause of C and strengthens B as the cause.