Aptitude - Probability - Discussion
Discussion Forum : Probability - General Questions (Q.No. 12)
12.
A bag contains 4 white, 5 red and 6 blue balls. Three balls are drawn at random from the bag. The probability that all of them are red, is:
Answer: Option
Explanation:
Let S be the sample space.
| Then, n(S) | = number of ways of drawing 3 balls out of 15 | |||
| = 15C3 | ||||
|
||||
| = 455. |
Let E = event of getting all the 3 red balls.
 n(E) = 5C3 = 5C2 = |
(5 x 4) | = 10. |
| (2 x 1) |
| P(E) = |
n(E) | = | 10 | = | 2 | . |
| n(S) | 455 | 91 |
Discussion:
33 comments Page 3 of 4.
Shiva said:
7 years ago
Why not 3/5 for selecting 3 red balls from total 5 red balls?
(1)
Smrutiranjan Routray said:
2 years ago
Only red ball means;
5/15 * 4/14 * 3/13 = 60/2730 = 2/91.
5/15 * 4/14 * 3/13 = 60/2730 = 2/91.
(5)
Jino said:
4 years ago
@Deki Zangmo.
Thanks for the clear and best explanation.
Thanks for the clear and best explanation.
(1)
Pavanmahesh said:
5 years ago
All of them red balls means why it can be a 15c3?
Rahul. Moorkoth said:
7 years ago
According to me, the Answer should be 4/91.
(1)
Divya said:
1 decade ago
How come 5C3 become 5C2? please explain.
Chetan said:
8 years ago
Good explanation, Thanks @Rohit.
Pandu raju said:
9 years ago
Thank you for the explanation.
Subash said:
6 years ago
Can any one explain clearly.
Hiren said:
9 years ago
I like your logic @Dharika.
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