Question

Nick tosses three coins simultaneously. What is the probability of getting at least two heads?

• A. $\frac{3}{4}$
• B. $\frac{5}{8}$
• C. $\frac{7}{8}$
• D. $\frac{1}{2}$

Answer 1

The correct option is D $\frac{1}{2}$

Let E be the event 'getting at least two head'.
Sample space, S = {(HHH), (HHT), (HTH), (THH), (THT),(TTH), (HTT), (TTT)}.
Total no. of outcomes n(S) = 8
Favourable outcomes for 'getting atleast two heads', F = {(HHH), (HHT), (HTH), (THH)}.
$\therefore$ No. of favourable outcomes = 4
$\text{Probability P(E)}$ = $\frac{\text{Number of outcomes favorable to E}}{\text{Number of all possible outcomes of the experiment}}$ = $\frac{4}{8}$ = $\frac{1}{2}$