Question

If a fair coin is tossed six times. What is the probability of getting at least three heads?

Answer 1

Probability of getting atleast three heads $=$probability of getting $3$ heads$+$probability of getting $4$ heads

$+$probability of getting $5$ heads $+$probability of getting $6$ heads

$=\frac{{(}^6{C}_3{+}^6{C}_4{+}^6{C}_5{+}^6{C}_6)6!}{2^6\times 6!}=\frac{20+15+6+1}{64}=\frac{42}{64}$

$=\frac{21}{32}$