Question

Three coins are tossed together, then the probability of getting atleast one tail is

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

Answer 1

Answer: (B)

When three coins are tossed together, then sample T space
$(HHH),(HHT),(HTT),(HTH),$
$(THH),(THT),(TTT),(TTH)$
$\Rightarrow$ $n(S)=8$
Number of ways to get atleast one tail
$=(HHT),(HTT),(TTT),(HTH),(THT),(THH),$
$(TTH)$ $n(E)=7$
$\therefore$ Probability, $P(E)=\frac{n(E)}{n(S)}=\frac{7}{8}$