Aptitude - Probability - Discussion
Discussion Forum : Probability - General Questions (Q.No. 7)
7.
In a class, there are 15 boys and 10 girls. Three students are selected at random. The probability that 1 girl and 2 boys are selected, is:
Answer: Option
Explanation:
Let S be the sample space and E be the event of selecting 1 girl and 2 boys.
| Then, n(S) | = Number ways of selecting 3 students out of 25 | |||
| = 25C3 ` | ||||
|
||||
| = 2300. |
| n(E) | = (10C1 x 15C2) | ||||||
|
|||||||
| = 1050. |
 P(E) = |
n(E) | = | 1050 | = | 21 | . |
| n(S) | 2300 | 46 |
Discussion:
54 comments Page 3 of 6.
Kuldeep said:
8 years ago
Thanks @Sanjana.
Shikha said:
8 years ago
I am not able to understand this answer please some one clear my doubt.
Mary-ann said:
10 years ago
I can't understand someone help.
Deel khus said:
8 years ago
@Prabhu.
They are multiplied bc.
The rule of calculating probability is that if getting a or b then we must be added the probability and if getting a and b then its probability must be multiplied.
They are multiplied bc.
The rule of calculating probability is that if getting a or b then we must be added the probability and if getting a and b then its probability must be multiplied.
Shekhar Gupta said:
8 years ago
To select boy and girls are mutually independent events. So they are multiplied.
Thanos said:
5 years ago
@Jay Lee Lord.
Thank You for your answer.
Thank You for your answer.
Daniel ocen said:
3 months ago
I can't understand this, someone help me to get it.
Annie said:
1 decade ago
@Abhi
Because we do not care about the order in which we pick the boys and girls.
Also, if you picked the boys and girls in a different order than the one you used, wouldn't it be a different answer? So we don't solve it like x/25 x y/24 x z/23
Because we do not care about the order in which we pick the boys and girls.
Also, if you picked the boys and girls in a different order than the one you used, wouldn't it be a different answer? So we don't solve it like x/25 x y/24 x z/23
Priya said:
1 decade ago
@prabhu.
Even I have the same doubt. Can some intellectual person answer this?
Even I have the same doubt. Can some intellectual person answer this?
Gnana said:
1 decade ago
I too have same doubt. Can any one clarify this, soon.
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