Let P(A) be the probability of students studying mathematics.
∴ P(A) = 0.40
Let P(B) be the probability of students studying biology.
∴ P(B) = 0.25
Let P(A ∩ B) be the probability of students studying both mathematics and biology.
∴ P(A∩B)=0.15
One student is selected at random.
Tip – By conditional probability, P(A/B) = \(\frac{P(A\cap B)}{P(B)}\) where P(A/B) is the probability of occurrence of the event
A given that B has already occurred.
(i) The probability that he studies mathematics given that he studies biology:
(ii) The probability that he studies biology given that he studies mathematics: