Question

three unbaised coins are tossed together. find the probability of getting :
I) all heads
II) exactly two heads
III) at least two heads
IV) almost to heads​

Answer 1

Answer:Sample  space  of  tossing 3 coins together (Set  of total possible  events know  as  sample space)

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

n(S) = 8

i) One head

Events  having  one head,

E = {TTH , THT , HTT}

n(E) = 3

Hence,

Probability of  getting one head = n(E)/n(S) = 3/8

ii)Two heads

Events  having  two head,

E = {THH ,HHT , HTH}

n(E) = 3

Hence,

Probability of  getting one head = n(E)/n(S) = 3/8

(iii) All heads

Events  having  all heads,

E = {HHH}

n(E) = 1

Hence,

Probability of  getting one head = n(E)/n(S) = 1/8

(iv) at least two heads:- It means that at  heads two heads or  more that two as more as possible.

Events  having at least two heads,

E = {HHT, HHT , HTH , HHH}

n(E) = 4

Hence,

Probability of  getting one head = n(E)/n(S) = 4/8 = 1/2

Step-by-step explanation:

Answer 2

Answer:

(i) 1/8

=} Total outcome =8

no. of favourable outcome= 1

So,that is 1/8.

{H,H,H},{H,H,T},{H,T,T},{T,H,H},{T,H,T}{H,TT},{T,T,T},{H,T,H}.

there is total 8 outcome.

(ii) Favourable outcome =3

so, probability is 3/8

(iii) at least 2 head means 2 head or more than 2 head .

favourable outcome=4

probability is 4/8

(iv) at most two head means 2 head or less than 2 head.

so, favourable outcome is 7

probability is 7/8

Hope it help you

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