Question

Three coins are tossed simultaneously once. Find the probability of getting

(i) at least one tail (ii) no tail.

Answer 1

Sample space when three coins tossed: $HHH,HHT,HTH,HTT,THH,THT,TTH,TTT$

Total outcomes $=8$

No. of outcomes in which there is at least one tail $=7$

No. of outcomes having no tail $=1$

(i) P (getting at least one tail) $=\frac{\text{No. of outcomes in which there is at least one tail}}{\text{Total outcomes}}=\frac{7}{8}$

(ii) P (getting no tail) $=\frac{\text{No. of outcomes having no tail}}{\text{Total outcomes}}=\frac{1}{8}$