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 12 of 14.
Kiprono Langat Esau said:
9 years ago
Kindly, solve this.
The committee of six is to be formed from a group of seven engineers and four mathematicians, how many different committees can be formed if at least two mathematicians are always to be included?
The committee of six is to be formed from a group of seven engineers and four mathematicians, how many different committees can be formed if at least two mathematicians are always to be included?
Siva kumar said:
9 years ago
Nice solution @Nagu.
Abhimanyu said:
9 years ago
756 WILL BE CORRECT.
35 * 15 + 35 * 6 + 21= 756.
35 * 15 + 35 * 6 + 21= 756.
Rutuja said:
9 years ago
Someone, please give the solution.
In a group of 6 people, there are 3 Indians and 3 Chinese. How many subsets can be created such that there are at least 1 Indian in each subset?
In a group of 6 people, there are 3 Indians and 3 Chinese. How many subsets can be created such that there are at least 1 Indian in each subset?
Harsh said:
9 years ago
It's correct that we select 3 men from 7 and 2 women from 6. But why do we need to multiply it to get total no of ways?
Shoeib said:
9 years ago
Yeah, I too agree @Harsh.
Ali said:
8 years ago
@Harsh.
I think we need to multiply so that we get the total number of ways we can choose 3 men from a total of 13 men and women.
I think we need to multiply so that we get the total number of ways we can choose 3 men from a total of 13 men and women.
Mamta Patel said:
8 years ago
The total number of combinations possible: 13C5=1287.
Then Calculate the number of combinations with less than 3 men in them: 7C2*6C3=21*20=420 7C1*6C4=7*15=105 7C0*6C5=1*6=6.
After that deduct the number of combinations with less than 3 men from total number of combinations: 1287-(420+105+6)= 756.
Then Calculate the number of combinations with less than 3 men in them: 7C2*6C3=21*20=420 7C1*6C4=7*15=105 7C0*6C5=1*6=6.
After that deduct the number of combinations with less than 3 men from total number of combinations: 1287-(420+105+6)= 756.
Aryabhatt said:
8 years ago
Why don't we apply permutation after getting the answer 756 to get the number of ways those 5 persons can be arranged?
Felix said:
8 years ago
How is 7c3 = 35?
Post your comments here:
Quick links
Quantitative Aptitude
Verbal (English)
Reasoning
Programming
Interview
Placement Papers