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Tell me? Minimum number of times a fair coin must be tossed so thatthe probability of getting at least one head is more than 99% is :

Minimum number of times a fair coin must be tossed so that

the probability of getting at least one head is more than 99% is :

  • Option 1)

    5

  • Option 2)

    6

  • Option 3)

    8

  • Option 4)

    7

 
Answers (1)
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V Vakul

P(H)=\frac{1}{2}

So, probability to get atleast one head = 1-P(no\: \: head)\geq 99

\therefore  1-\frac{1}{2^{n}}\geq \frac{99}{100}

=>\frac{1}{2^{n}}\leq \frac{1}{100}

=>{2^{n}}\geq {100}

=>n\geq 7

\therefore Minimum value of n will be = 7

So, option (4) is correct. 


Option 1)

5

Option 2)

6

Option 3)

8

Option 4)

7

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