Aptitude - Permutation and Combination - Discussion
Discussion Forum : Permutation and Combination - General Questions (Q.No. 1)
1.
From a group of 7 men and 6 women, five persons are to be selected to form a committee so that at least 3 men are there on the committee. In how many ways can it be done?
Answer: Option
Explanation:
We may have (3 men and 2 women) or (4 men and 1 woman) or (5 men only).
 Required number of ways |
= (7C3 x 6C2) + (7C4 x 6C1) + (7C5) | |||||||||||
|
||||||||||||
|
||||||||||||
| = (525 + 210 + 21) | ||||||||||||
| = 756. |
Discussion:
137 comments Page 13 of 14.
Naina said:
8 years ago
What are the number of ways to select 3 men and 2 women such that one man and one woman are always selected?
The Answer is 30 and solution is 4c2 * 5c1.
But, I don't think it is right according to the condition given in the question.
Someone help me.
The Answer is 30 and solution is 4c2 * 5c1.
But, I don't think it is right according to the condition given in the question.
Someone help me.
Abhijit said:
8 years ago
I tried to solve like this.
Out of 7 places first 3 places to be filled by men so.. 7*6*5 = 42*5 ways but order does not matter so removing redundancies (42*5)/3!.
Similarly Remaining two places can be filled in (10*9)/2!.
Final answer is same as 7C3 * 10C2.
Out of 7 places first 3 places to be filled by men so.. 7*6*5 = 42*5 ways but order does not matter so removing redundancies (42*5)/3!.
Similarly Remaining two places can be filled in (10*9)/2!.
Final answer is same as 7C3 * 10C2.
Tshewang chophel said:
8 years ago
How to get 7c3=35?
Udoy said:
8 years ago
When do we add or multiply ?
Manuel said:
8 years ago
Help me knowing how to solve this kind of equation I'm doing my Student Individual Learning Plan.
I need to proof that I was correct so help me please.
I need to proof that I was correct so help me please.
Calesto said:
8 years ago
I don't understand why 7C5, in which 5is total number of persons to be chosen where 3 are men and remaining two are obviously women.
Thus, the answer should be 735.
Thus, the answer should be 735.
Teja said:
7 years ago
Here, ncr=nc(n-r).
Pratheeksha said:
7 years ago
Yes, 756 is a right ans.
Bcause out of 13(7men+6women) we have to select 5.Therefore
7men(5)6women,
7C3 X 6C2=35(15)=525,
7C4 X 6C1=35(6)=210,
7C5 X 6C0=21(1)=21,
=756.
Therefore, 756 is the answer.
Bcause out of 13(7men+6women) we have to select 5.Therefore
7men(5)6women,
7C3 X 6C2=35(15)=525,
7C4 X 6C1=35(6)=210,
7C5 X 6C0=21(1)=21,
=756.
Therefore, 756 is the answer.
Vamsi mvk said:
7 years ago
@Pavz.
Thanks for your explanation.
Thanks for your explanation.
Dimi said:
7 years ago
I have a question, in how many ways can a committee of nine people can be formed from ten men and their wives. If no man is to serve on the committee with his wife?
Please solve this.
Please solve this.
Post your comments here:
Quick links
Quantitative Aptitude
Verbal (English)
Reasoning
Programming
Interview
Placement Papers