ferrarih wrote:

In a grouup of 800 people, 1/5 play at least one instrument, 96 play two or more. Whats it is e probability that one student play exactly one instrument?

A) 2/125

B) 3/125

C)2/25

D) 3/25

E) 1/5

P(playing 2 or more instruments) = 96/800 = 3/25.

Then, the probability of playing exactly one instrument is given by:

P(playing 1 or more instruments) - P(playing 2 or more instruments) = 1/5 - 3/25 = 2/25.

Answer C.

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