Question

In a school of 1250 students, 250 are freshmen and 150 students take Spanish. The probability that a student takes Spanish given that he/she is a freshman is 30%. What is the probability that a randomly selected student is a freshman given that he/she takes Spanish?

Answer 1

The answer is C. 50%

Explanation:

Let F = freshman and S = Spanish student.

P(F) = 250 /1250 = 20%

P(S) = 150 /1250 = 12%

P(S|F) = P(S∩F) /250 = 30%

⇒ P(S∩F) = 250 · 30% = 75

P(F|S) = P(S∩F) /150 = 75 /150 = 50%

Answer 2

20% hope I helped :)