During the past week, a local medical clinic tested N individuals for two infections. If 1/2 of those tested had infection A and, of those with infection A, 1/6 also had infection B, how many individuals did not have both infection A and B?  Select the correct option: A) N/12 B) 4N/15 C) 14N/12 D) 11N/12 E) 4N/5
1/3 of tested had infection A, thus N/2 had infection A;   Of those with infection A, 1/6 also had infection B, thus 1/2*N/6 = N/12 had both infections A and B.   Therefore, N - N/12 = 11N/12 did not have both infection A and B.   Answer: 11N/12.
<result>D</result>
During the past week, a local medical clinic tested N individuals for two infections. If 1/2 of those tested had infection A and, of those with infection A, 1/6 also had infection B, how many individuals did not have both infection A and B?