An ordinary dice is rolled for a certain number of times. If the probability of getting an odd number 2…

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:
  1. 132
  2. 516
  3. 316
  4. 12

Solution

C2n12n=C3n12nC2n=C3n

  n=5

Probability of getting an odd number for odd number of times is

C15125+C35125+C55125=1255+10+1

=12

Asked in: JEE Main 2021 (24 Feb Shift 1)

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