Aptitude - Probability - Discussion
Discussion Forum : Probability - General Questions (Q.No. 5)
5.
Three unbiased coins are tossed. What is the probability of getting at most two heads?
Answer: Option
Explanation:
Here S = {TTT, TTH, THT, HTT, THH, HTH, HHT, HHH}
Let E = event of getting at most two heads.
Then E = {TTT, TTH, THT, HTT, THH, HTH, HHT}.
 P(E) = |
n(E) | = | 7 | . |
| n(S) | 8 |
Discussion:
121 comments Page 4 of 13.
Arun Kumar said:
7 years ago
@All.
Note : At most means upto two heads not more than it.
Note : At most means upto two heads not more than it.
Arnika said:
7 years ago
I can't understand this, please anyone help me to get the answer clearly.
D.Harshali said:
7 years ago
Hi, guys my self Harshali. Discussing this question the answer is 1/2.
As p(E) = 8 and Event is getting two heads means it also includes 3 heads.
So, n(E) = (THH,HHT,THT.HHH).
P(E) = n(E)/n(P).
= 4/8.
= 1/2.
As p(E) = 8 and Event is getting two heads means it also includes 3 heads.
So, n(E) = (THH,HHT,THT.HHH).
P(E) = n(E)/n(P).
= 4/8.
= 1/2.
Afsha said:
7 years ago
At most means not more than;
Here, it's not more than 2. Thus, n(E) = 3.
Therefore, p(E) = 3/8.
Here, it's not more than 2. Thus, n(E) = 3.
Therefore, p(E) = 3/8.
Sunny said:
7 years ago
At most two head means there can be 0, 1 or 2 heads not more than 2.
Awaneesh Kumar said:
7 years ago
I do not understand about this answer, because most two heads coming from events.
I think the ans is 3/8.
TTT in not come head
TTH
THT
HTT
have not come head most times.
I think the ans is 3/8.
TTT in not come head
TTH
THT
HTT
have not come head most times.
Raghav said:
7 years ago
We can solve with combination too.
Sample space will be 2^3=8, we are taking base 2 because there are two instances; head or tails. Atmost 2 heads mean, that maximum no. Of heads include are 2, this means that the case of 0 head will also be included.
So, it will be (3c0+3c1+3c2) /8 i.e. (case with 0 head+case with 1head+case with 2 head) / sample space= 7/8.
Sample space will be 2^3=8, we are taking base 2 because there are two instances; head or tails. Atmost 2 heads mean, that maximum no. Of heads include are 2, this means that the case of 0 head will also be included.
So, it will be (3c0+3c1+3c2) /8 i.e. (case with 0 head+case with 1head+case with 2 head) / sample space= 7/8.
Sridevi said:
7 years ago
Can anyone explain it to me?
Sridevi said:
7 years ago
Why we have to take (TTT) ?
I can't understand.
I can't understand.
Eraiarul said:
7 years ago
Thanks all.
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