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 7 of 14.
Leo said:
1 decade ago
--> (7C3 x 6C2) + (7C4 x 6C1) + (7C5)
Shouldn't it be like this? --> (7C3 x 6C2) x (7C4 x 6C1) x (7C5)
Shouldn't it be like this? --> (7C3 x 6C2) x (7C4 x 6C1) x (7C5)
Lana said:
1 decade ago
Hey can any one explain me how 210 came because I got 140 instead of 210.
Lookin forward for your support.
Lookin forward for your support.
Akshay said:
1 decade ago
@Venki.
If the order doesn't matter, it is a Combination.
If the order does matter it is a Permutation.
If the order doesn't matter, it is a Combination.
If the order does matter it is a Permutation.
Khan said:
1 year ago
Why can't it be, 7C3 (at least 3 men) * 10C2 (any 2 may be men or women or both out of the remaining 10)?
(21)
Swetha said:
1 decade ago
@Divya as in que asked as at least 3 men should be available in a group so we can't take 5 women. right?
Anil said:
9 years ago
@Malu.
The problem says at least 3 men so if you select 5 women it would contradiction to the problem.
The problem says at least 3 men so if you select 5 women it would contradiction to the problem.
Sri Ram said:
1 decade ago
Is there any shortcut for doing the steps like 13c5 like that. These steps are taking too much time?
Malu said:
9 years ago
Why can't we select only five women out of 6 women. Why that combination is not taken into account.
Sam said:
1 decade ago
Can you please explain 7c5 is converted into nc(n-r)?
But why didn't convert 6c2 into 6c(6-2)?
But why didn't convert 6c2 into 6c(6-2)?
ANBU said:
1 decade ago
@Pankaj.
They asked at least 3 men not compulsory 3 men so 4men and 5 men is also possibility.
They asked at least 3 men not compulsory 3 men so 4men and 5 men is also possibility.
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