two unbiased coins are tossed simultaneously.find the probability of getting at most 1 head

Asked by arushi | 21st Feb, 2014, 08:06: PM

Expert Answer:

When two coins are tossed simultaneously then the possible outcomes obtained are {HH, HT, TH, and TT}.

Here H denotes head and T denotes tail.

Therefore, a total of 4 outcomes obtained on tossing two coins simultaneously.


Consider the event of obtaining at the most one head. At most one head is obtained means either no head is obtained or one head is obtained.


The outcome(s) favourable to no head obtained is {TT}

The outcome(s) favourable to one head obtained is {HT, TH}


Therefore, the event of obtaining at most one head has 3 favourable outcomes. These are TT, HT and TH.


Therefore, the probability of obtaining at most one head = 3/4.

Answered by  | 21st Feb, 2014, 10:40: PM

Queries asked on Sunday & after 7pm from Monday to Saturday will be answered after 12pm the next working day.