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A bag contains five white and four red balls. Two balls are picked at random from the bag. What is the probability that they both are different color?

Correct answer: B. 5/9

  • A. 4/9
  • B. 5/9
  • C. 7/9
  • D. 8/9

Explanation

There are 5 x 4 = 20 favorable pairs with one white and one red ball, out of C(9,2) = 36 total pairs. Thus the probability is 20/36 = 5/9. The likely wrong choice is 4/9, which reverses the favorable and total counts or treats the two colours as equally numerous.

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