Discussion Forum

A coin is tossed three times if X denotes the absolute difference between the number of heads and the number of heads and the number of tails, then P(X =1) = 

Answer:

Explanation:

 Given, 

A coin is tossed three times

and X= absolute difference between the number of heads and number of tails

 Now, X= 1 when exactly two head or two  tail comes

 $\therefore$     $P(X=1)=\frac{3}{8}+\frac{3}{8}=\frac{6}{8}=\frac{3}{4}$

           [ $\because$ probability of exactlly two head= $\frac{3}{8}$

                and probability of exactly  two tails= $\frac{3}{8}$]