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.
Pravin patel said:
1 decade ago
@LETTISHA.
Possibility is head or tail, mean 2 time.
And it is to 3 time means 2^3 = 8(2*2*2) = 8.
Hear is coin, if we are using dies then 6^3.
Possibility is head or tail, mean 2 time.
And it is to 3 time means 2^3 = 8(2*2*2) = 8.
Hear is coin, if we are using dies then 6^3.
Manan said:
1 decade ago
Can't it be like this:
Probability of all events = 3 heads, 2 heads, 1 head, 0 heads.
Hence n(s) = 4.
n(e) = 3.
Probability = 3/4.
Probability of all events = 3 heads, 2 heads, 1 head, 0 heads.
Hence n(s) = 4.
n(e) = 3.
Probability = 3/4.
Sonali malviya said:
1 decade ago
Can anybody tell me why we have taken n(e) = 7?
Ghanshyam said:
1 decade ago
How P(E) = n(E) upon n(S)= 7 by 8.
Riems said:
1 decade ago
Is there any direct method for calculating it? Because calculating n(e) may get confused in the exams time.
Brian said:
1 decade ago
What is the probability of this question?
Joel said:
1 decade ago
At most 2 heads, so how did you include HHH?
Venkat said:
1 decade ago
Answer is 3/8 i.e. (C).
H T H.
H H T.
T H H.
H T H.
H H T.
T H H.
Rajesh said:
1 decade ago
At most means 7/8.
At leat means 3/8.
At leat means 3/8.
Manu said:
1 decade ago
Thanks very helpful.
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