Two coins are tossed simultaneously. Find the probability of getting

(i) Exactly 1 head


(ii) At most 1 head


(iii) At least 1 head

When two coins are tossed simultaneously, all possible outcomes are HH, HT, TH, TT.


Total number of outcomes = 4


(i) Let E be the event for getting exactly 1 head


Then, the favourable outcomes are: HT, TH


Number of favourable outcomes = 2


P(getting exactly one head) = P(E) = 2/4 = 1/2 or 50%


(ii) Let E be the event for getting atmost one head


Then, the favourable outcomes are: HT, TH, HH


Number of favourable outcomes = 3


P(getting atmost one head) = P(E) = 3/4 or 75%


Note: Atmost one means maximum one head can come. So, we will also consider the outcome in which no head is obtained.


Atleast one means minimum one head will come. So, the outcome with two heads will also be counted.


(iii) Let E be the event for getting atleast one head


Then, the favourable outcomes are: HT, TH, HH


Number of favourable outcomes = 3


P(getting atleast one head) = P(E) = 3/4 or 75%


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