If two unbiased coins are tossed simultaneously, then the total outcomes may be HH, HT, TH, TT..
No. of total outcomes = 4
(i) two heads
favourable outcome for two heads are HH.
No. of favourable outcomes = 1
P(two heads) =
(ii) favourable outcome for one tail are TH, HT .
No. of favourable outcomes = 2
P(one tail) =
(iii) favourable outcome for at least one tail are are TH, HT, TT .
No. of favourable outcomes = 3
P(at least one tail) =
(vi) favourable outcome for at least one head are are TH, HT, HH .
No. of favourable outcomes = 3
P(at least one head) =
(v) favourable outcome for no tail are HH .
No. of favourable outcomes = 1
P(no tail) =