Question

Urn A contains 6 red and 4 black balls and urn B contains 4 red and 6 black balls. One ball is drawn at random from urn A and placed in urn B. Then, one ball is drawn at random from urn B and placed in urn A. If one ball is drawn at random from urn A, the probability that it is found to be red, is.... Select the correct answer from above options

Answer 1

Correct Answer - B::C Let R be drawing a red ball and B for drawing a black ball, then required probability =ℝR+RBR+Bℝ+BBR =( 6 10 × 5 11 × 6 10 )+( 6 10 × 6 11 × 5 10 )+( 4 10 × 4 11 × 7 10 )( 4 10 × 7 11 × 6 10 ) = 640 1100 = 32 55