GMAT Problem Solving (PS) | Re: A fair coin is tossed 4 times. What is the probability of

This is a standard question, which should be approach with a general concept.
Otherwise, it is a waste of time to reconstruct the logic everytime we face this type of question.

The oncept is binomial variable probabilities.

Proba of having k success out-of n events for a binomial variable is given by a formula.
Let say, proba of success = p and proba of failure = (1-p)

Formula is nCk * (p^k)*(1-p)^(n-k)
if p=1/2 then formula becomes nCk/(2^n)

In the current question, p=1/2 and (1-p)=1/2
n=4
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