Question

Three unbiased coins are tossed together. Find the probability of getting:
at least two heads.

Answer 1

Elementary events associated to random experiment of tossing three coins are HHH, HHT, HTH, THH, HTT, THT, TTH, TTT
$\therefore$ total number of elementary events = 8.
If any of the elementary events HHH, HHT, HTH and THH is an outcome, then we say that the event "Getting at least two heads" occurs.
$\therefore$ Favourable number of elementary events = 4
Hence, required probability = $\frac{4}{8}=\frac{1}{2}$