Aptitude - Probability - Discussion
Discussion Forum : Probability - General Questions (Q.No. 2)
2.
A bag contains 2 red, 3 green and 2 blue balls. Two balls are drawn at random. What is the probability that none of the balls drawn is blue?
Answer: Option
Explanation:
Total number of balls = (2 + 3 + 2) = 7.
Let S be the sample space.
| Then, n(S) | = Number of ways of drawing 2 balls out of 7 | |||
| = 7C2 ` | ||||
|
||||
| = 21. |
Let E = Event of drawing 2 balls, none of which is blue.
 n(E) |
= Number of ways of drawing 2 balls out of (2 + 3) balls. | |||
| = 5C2 | ||||
|
||||
| = 10. |
| P(E) = |
n(E) | = | 10 | . |
| n(S) | 21 |
Discussion:
116 comments Page 9 of 12.
Piyul said:
1 decade ago
Is there any other way to understand basic concept of probability?
Hari said:
1 decade ago
Supriya c2 means multiply with number below it. Suppose 2c2= 2*1.
Ekta said:
1 decade ago
Please clarify it which one having best answer of the solution.
Trini said:
7 years ago
7c2 -> 7!/(7-2)! 2! which is 7*6*5!/5!2! = 7*6/2*1 = 21.
Saravana said:
9 years ago
What is the need for finding the first step? Please Explain.
Christiano ronaldo said:
7 years ago
I didn't understand this. Please, anyone, help me to get it.
Bikash said:
8 years ago
Can you please explain in detail what is mean by C and all?
SALONI said:
10 years ago
How we can know that we need to use ''C'' formula in sum ?
Rose were said:
1 decade ago
How did the multiplications come about? please answer me.
Roma said:
9 years ago
You are right Saurabh, in my way the method 1 is correct.
Post your comments here:
Quick links
Quantitative Aptitude
Verbal (English)
Reasoning
Programming
Interview
Placement Papers