4,090 views
2 votes
2 votes
A fair coin is tossed n times .find probability of difference between head and tails is n-3

2 Answers

6 votes
6 votes
if n=2 S={HH,HT,TH,TT} difference is 0 ,2 so n-3 ie -1 not possible

if n=3 S={HHH HHT HTH HTT THH THT TTH TTT}

here difference is 3,1, and n-3 =0 not possible

for n= even n-3 is odd and difference between head and tail will be always even

for n= odd n-3 is even and difference between head and tail will always odd

so  probability=0
1 votes
1 votes

 


when n = probability of occurrence of head 
y = probability of occurrence of tail 
Let number of head is P
Number of tail is q

Here required probability is zero.

Related questions

0 votes
0 votes
0 answers
1
srestha asked Mar 21, 2018
440 views
A coin is tossed ,the probability of getting heads p,o<p<1. Let N be random variable denoting the number of tosses where the head ans tail comes simulteneously and no tw...
5 votes
5 votes
3 answers
3
dd asked Sep 24, 2016
2,849 views
An unbiased coin is tossed repeatedly and outcomes are recorded. What is the expected no of toss to get HT ( one head and one tail consecutively) ?
3 votes
3 votes
2 answers
4
Pooja Palod asked Dec 16, 2015
5,250 views
an unbiased coin is tossed infinite no of times.The probability that 4th head appear at 10th toss is 1) 0.0672) 0.0733) 0.0824) 0.091