For what percent of those tested for a certain infection was the test accurate; that is, positive for those who had the

[Vincen]

For what percent of those tested for a certain infection was the test accurate; that is, positive for those who had the infection and negative for those who did not have the infection?

(1) Of those who tested positive for the infection,1/8 did not have the infection.
(2) Of those tested for the infection, 90 percent tested negative.

Answer: E

Source: GMAT Prep