SOLUTION: Suppose that a certain college class contains 62 students. Of these, 34 are sophomores, 35 are psychology majors, and 7 are neither. A student is selected at random from the class.

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Question 634869: Suppose that a certain college class contains 62 students. Of these, 34 are sophomores, 35 are psychology majors, and 7 are neither. A student is selected at random from the class.
a) What is the probability that the student is both a sophomore and a psychology major?
(b) Given that the student selected is a sophomore, what is the probability that he is also a psychology major?
Answer by ewatrrr(24785) About Me  (Show Source):
You can put this solution on YOUR website!
 

Hi,

62 students. Of these, 34 are sophomores, 35 are psychology majors, and 7 are neither

 62-7 = 55 students are sophmores, psyc majors or both

 34 + 35 = 69 - 55 = 14 are both

a) What is the probability that the student is both a sophomore and a psychology major? P+=+14%2F62+=+7%2F31

 (b) Given that the student selected is a sophomore, what is the probability that he is also a psychology major?

 P = +%2814%2F62%29%2F%2834%2F62%29%0D%0A+=+14%2F34+=+7%2F17