Question

A class consists of 55% boys and 45% girls. It is observed that 25% of the class are boys and scored an A on the test, and 35% of the class are

girls and scored an A on the test.
If a student is chosen at random and is found to be a girl, the probability that the student scored an Ais

Answer 1

Explanation:

Probability of event A on the condition of event B is:

P(A|B) = P(A and B) / P(B)

P(scored an A | girl) = P(scored an A and girl) / P(girl)

P(scored an A | girl) = 0.35 / 0.45

P(scored an A | girl) = 0.778

The probability that a randomly selected girl also scored an A is 77.8%.