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AP EAMCET201823 Apr 2018Evening ShiftMathematicsProbabilityActual

An unbiased coin is tossed n times. If the probability of getting atleast one head is greater than 0.8 , then the least value of n is

Options

  1. A2
  2. B3
  3. C4
  4. D5

Correct answer

B. 3

Step-by-step solution

The probability of getting at least one head aligned & =1-( probability of getting no head) & =1- ^n C_n ( 1 2 )^n=1- ( 1 2 )^n>0.8 (given), & ( 1 2 )^n 5 aligned The least value of n is 3 .

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