During the past week, a local fish market tested N fish for two infections. If 1/10 of those tested had infection A and, of those with infection A, 1/5 also had infection B, how many fish did not have both infection A and B?
Choose the correct choice from the following choices.
A) N/15
B) 4N/15
C) 14N/15
D) N/5
E) 49N/50
1/10 of tested had infection A, thus N/10 had infection A;   Of those with infection A, 1/5 also had infection B, thus 1/5*N/10 = N/50 had both infections A and B.   Therefore, N - N/50 = 49/50 did not have both infection A and B.   Answer: 49N/50.
<result>E</result>
During the past week, a local fish market tested N fish for two infections. If 1/10 of those tested had infection A and, of those with infection A, 1/5 also had infection B, how many fish did not have both infection A and B?