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JEE Main202124 Feb 2021Morning ShiftMathematicsProbabilityActual

An ordinary dice is rolled for a certain number of times. If the probability of getting an odd number 2 times is equal to the probability of getting an even number 3 times, then the probability of getting an odd number for odd number of times is:

Options

  1. A1 32
  2. B5 16
  3. C3 16
  4. D1 2

Correct answer

D. 1 2

Step-by-step solution

C 2 n 1 2 n = C 3 n 1 2 n ⇒ C 2 n = C 3 n ⇒    n = 5 Probability of getting an odd number for odd number of times is C 1 5 1 2 5 + C 3 5 1 2 5 + C 5 5 1 2 5 = 1 2 5 5 + 10 + 1 = 1 2

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