Question

The probability of getting 'atmost two heads' on tossing three coins simultaneously is.

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

Answer 1

The correct option is C $\frac{7}{8}$

Sample space = {HHH, HHT, HTH, THH, TTT, THT, TTH, HTT)
Total no. of outcomes = 8
Atmost two heads means: 0 head, 1 head, 2 head.
Favourable outcomes ( for atmost two heads) = (HHT, HTH, THH, TTT, THT, TTH, HTT)
Number of favorable outcomes = 7
$\therefore$ Required probability = $\frac{7}{8}$