In a large school, it was found that 33% of students are taking a math class, 36% of student are taking an English class, and 14% of students are taking both.

Question

a.) Find the probability that a randomly selected student is taking a math class or an English class. Write your answer as a decimal, and round to 2 decimal places if necessary.

b.) Find the probability that a randomly selected student is taking neither a math class nor an English class. Write your answer as a decimal, and round to 2 decimal places if necessary.

Answer 1

a) P(A U B) = P(A) + P(B) - P(A ∩ B) = .33 + .36 - .14 = .55

b) P(~(A U B) ) = 1 - P(A U B) = 1 - .55 = .45