Question

. In a class, 50% of the students study physics and Biology. 70% of the students study physics. What is the probability of a student studying Biology given he/she is already studying physics?

Answer 1

P(A) = 0.7 = the probability of students study physics

P(B) = the probability of students study biology

The probability of students study physics and biology

$P(A \cap B) = 0.5$

The probability of a student studying Biology given he/she is already studying physics:

$P(B|A) = \frac{P(B \cap A)}{P(A)} \\ = \frac{0.5}{0.7} \\ = 0.7142$