Sample space = {HHH, HTH, HHT, THH, TTH, THT, HTT, TTT }

No. of favourable outcomes = 7

(i) P(at least one tail) = 7/8

No. of favourable outcomes = 1

(ii) P(no tail) = 1/8

Correct option is: A) \(\frac{7}{8}\)

When three coins are tossed simultaneously once.

Then total possible outcomes are

{HHH, HHT, HTH, THH, HTT, THT, TTH, TTT}

\(\therefore\) Total possible outcomes is n (S) = 8

Favourable outcomes to the even of getting at least one tail are

{HHT, HTH, THH, HTT, THT, TTH, TTT}

\(\therefore\) Total No of favourable outcomes = 7

\(\therefore\) Probability of getting at least one tail

= \(\frac {Total \,No\, of \,favourable \,outcomes}{Total \,Possible \, outcomes}\)

= \(\frac 78\)

Hence, probability of getting at least one tail is \(\frac 78\)

Correct option is: A) \(\frac{7}{8}\)