IndiaBIX

Aptitude - Permutation and Combination - Discussion

Discussion Forum : Permutation and Combination - General Questions (Q.No. 1)
Permutation and Combination
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?
564
645
735
756
None of these
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)
= 7 x 6 x 5 x 6 x 5 + (7C3 x 6C1) + (7C2)
3 x 2 x 1 2 x 1
= 525 + 7 x 6 x 5 x 6 + 7 x 6
3 x 2 x 1 2 x 1
= (525 + 210 + 21)
= 756.

Discussion:
137 comments Page 13 of 14.
Kumamako said:   1 decade ago
I think that it should be 3*2^3*3-3
Akshay said:   10 years ago
How 6C2 equal to 15 please explain?
Naveen Kumar said:   1 decade ago
Why we are calculating 7C5 as 7C2?
Kavya said:   7 months ago
How to solve this? Please explain.
(5)
Ananya said:   1 decade ago
Is there any shortcut for this?
Randika said:   1 decade ago
What is meant by nCr=nCn-r ?
Udoy said:   8 years ago
When do we add or multiply ?
Fatmata sorie said:   9 years ago
Where do you get from 35?
Shoeib said:   9 years ago
Yeah, I too agree @Harsh.
Renuka said:   1 decade ago
Because nCr = nCn-r.
Post your comments here:

Your comments will be displayed after verification.

Quick links
Quantitative Aptitude
Verbal (English)
Reasoning
Programming
Interview
Placement Papers