A coin is tossed 100 times , Find the probability that tail occurs odd number of times!
I do not know the answer, but I tried this, that there are these $4$ possible outcomes in which tossing of a coin $100$ times can unfold.
head occurs odd times
head occurs even times
tail occurs odd times
tail occurs even times
Getting a head is equally likely as getting a tail, similarly for odd times and even times. Thus, all of these events must have same the probability, i.e. $\dfrac{1}{4}$.
Is this the correct answer? Is there an alternate way of solving this problem? Lets hear it!