Question:
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:
[A].
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:
[A].
21 |
46 |
[B].
25 |
117 |
[C].
1 |
50 |
[D].
3 |
25 |
Answer: Option A
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 ` | ||||
|
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= 2300. |
n(E) | = (10C1 x 15C2) | ||||||
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= 1050. |
P(E) = | n(E) | = | 1050 | = | 21 | . |
n(S) | 2300 | 46 |