Question : A coin is tossed 2n times. The chance that the number of times one gets head is not equal to the number of times one gets tails is
(A) \dfrac{\left( 2n!\right) }{\left( n!\right) ^{2}}\left( \dfrac{1}{2}\right) ^{2n}
(B) 1-\dfrac{\left( 2n!\right) }{\left( n!\right) ^{2}}
(C) 1-\dfrac{\left( 2n!\right) }{\left( n!\right) ^{2}}\dfrac{1}{4^{n}}
(D) none of these
Answer : option (C)
Solution :
