Questionbank: Permutation and Probability

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Clue - FInd the number of rearrangements and then focus on the number of digits

Sum of Rearrangements

    Q.29: A bag contains 4 red and 3 black balls. A second bag contains 2 red and 3 black balls. One bag is selected at random. If from the selected bag one ball is drawn, then what is the probability that the ball drawn is red?


  • Correct Answer
    Choice D.

Detailed Solution

Let Red balls be 'r' and brown balls be 'b'

P(r) = p(b1) * p(r) + p(b2) * p(r)

P(R) =

P(R) =

Correct Answer :

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