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AP EAMCET2014MathematicsProbability

A six-faced unbiased die is thrown twice and the sum of the numbers appearing on the upper face is observed to be 7 . The probability that the number 3 has appeared atleast once, is

Options

  1. A1 5
  2. B2 5
  3. C3 5
  4. D4 5

Correct answer

C. 3 5

Step-by-step solution

Sum of the dice is 7 . aligned & S=- (1,6),(6,1),(2,5),(5,2),(3,4),(4,3) & n(S)=6 aligned Let, E= Event of getting atleast three 3 or a die n(E)=2 Required probability = n(E) n(S) = 2 6 = 1 3

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