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 2 of 4.
Dhruvil said:
1 decade ago
Probability = (5*4*3)/(15*14*13) = (6/273) = (2/91).
As there are 5 red balls in each bag.
As there are 5 red balls in each bag.
Alab said:
9 years ago
4 + 5 + 6 = 15.
First draw is 5/15.
Second 4/14.
Third 3/13.
(5/15)(4/14)(3/13) = 2/91
First draw is 5/15.
Second 4/14.
Third 3/13.
(5/15)(4/14)(3/13) = 2/91
(1)
USHA said:
1 decade ago
All of them red is possible only in one way so event is E= 5C1.
But how come 5c3 ?
But how come 5c3 ?
Somya said:
8 years ago
While calculating the term for red balls, why did we not consider the blue balls?
Keisha said:
9 years ago
S = 15.
e = 5/15 (red balls/total balls).
= 1/3.
Why is this not the answer?
e = 5/15 (red balls/total balls).
= 1/3.
Why is this not the answer?
Rohit said:
1 decade ago
1st red ball 5/15.
2nd red ball 4/14.
3rd red ball 3/13.
5*4*3/15*14*13 = 2/91.
2nd red ball 4/14.
3rd red ball 3/13.
5*4*3/15*14*13 = 2/91.
Sinchana said:
6 years ago
If the answer is 0.02 something how we can convert please explain it now.
(1)
Dinesh guptha said:
1 decade ago
Don't confuse divya.
Keep it as 5C3.
You will get the same ans.
Cool!
Keep it as 5C3.
You will get the same ans.
Cool!
Adnan Baig said:
2 years ago
Here it should be 5c3 becuase the selection of balls is 3 red balls.
(2)
SUDARSAN SWAIN said:
2 years ago
Why 5c2 is being calculated instead of 5c3? Please explain me.
(13)
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