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Three balls are marked with 2 , 4 and 6 . They are placed in a box and a ball is drawn, its number is noted and the ball drawn is returned to the box. The process is repeated two more times. If the probability of the sum of all the three numbers is 12 is λ, then 108 λ is equal to

Options

  1. A28
  2. B14
  3. C20
  4. D10

Correct answer

A. 28

Step-by-step solution

For the sum of all three numbers to be 12 , the possible cases are 2,4 , 6 , 4,4 , 4 Hence, required probability = 3 ! + 1 3 3 = 7 27

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