JEE Main 2024 Mathematics question
Bag A contains 3 white, 7 red balls and Bag B contains 3 white, 2 red balls. One bag is selected at random and a ball is drawn from it. The probability of drawing the ball from the bag A, if the ball drawn is white, is
Answer: (A)
Solution
By Bayes' theorem, P(A | white) = (½ × 3/10)/(½ × 3/10 + ½ × 3/5) = (3/20)/(3/20 + 3/10) = 1/3.