Question

Two unbiased coins are tossed simultaneously. Write the sample space. Find the probability of getting a) two heads b) one tail c) at least one head

Answer 1

the obs are hh th ht tt

out of these atleast onr head is present in hh th ht

thus probability of getting atleast 1 head is 3/4

only two obs ht and th have atmost 1 head

thus probability is 2/4 or 1/2

no head is there only in tt . so 1/4

Answer 2

Answer:

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

Here H denotes head and T denotes tail.

∴, 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  favourable to no head obtained is {TT}

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

∴, the event of obtaining at most one head has 3 favourable outcomes. 

These are TT,HT and TH.

∴, the probability of obtaining at most one head =43