There are two bag

Given: Bag A contains 3 white and 4 red balls while Bag B contains 4 white and 3 red balls

Let E₁ = Selecting bag A, E₂ = selecting bag B

Probability of selecting the bag is given by

Now the probability of the balls drawn from bag A

Total number of ways of getting 2 white and 1 red ball from bag A = ³C₂⁴C₁ = 12

Total possible outcome is = ⁷C₃ = 35

So

Now the probability of the balls drawn from bag B

Total number of ways of getting 2 white and 1 red ball from bag B = ⁴C₂³C₁ = 18

So,

Probability of the balls being drawn from bag B is given by

Formula: Bayes theorem

Hence, probability that these were drawn from bag B