Aptitude - Permutation and Combination - Discussion
Discussion Forum : Permutation and Combination - General Questions (Q.No. 11)
11.
In how many ways can a group of 5 men and 2 women be made out of a total of 7 men and 3 women?
Answer: Option
Explanation:
| Required number of ways = (7C5 x 3C2) = (7C2 x 3C1) = |  |
7 x 6 | x 3 |  |
= 63. |
| 2 x 1 |
Discussion:
51 comments Page 4 of 6.
Suvarna said:
1 decade ago
It takes more time to calculate 7c5 than 7c2& 3C2 than 3C1, to improve the speed we are doing like this.
Jat said:
1 decade ago
(7C5 x 3C2) = (7C2 x 3C1)
This step i can't understand.
Please explain me.
This step i can't understand.
Please explain me.
Manasa said:
1 decade ago
@jat
its just formula
n =n
c c
r n-r
n=7,r=5
7C5=7C2
its just formula
n =n
c c
r n-r
n=7,r=5
7C5=7C2
Zalak said:
1 decade ago
(7C5 x 3C2) = (7C2 x 3C1)
This step I can't understand. Please explain me.
This step I can't understand. Please explain me.
Kavu said:
1 decade ago
(7C2 x 3C1) = (7/2 x 6/1) x 3= 63.
How it comes?
How it comes?
ACHUTHARAJ said:
1 decade ago
Basic formula nCr = nCn-r
so 7C7-5 = 7C2
3C3-2 = 3C1
so 7C7-5 = 7C2
3C3-2 = 3C1
Divya said:
1 decade ago
How 3c2 change into 3c1?
Ankur anand said:
1 decade ago
Why combination why not permutation ?
Similar as that of the arranging of letters the people are diffrent so there can be many ways by permutation.
Similar as that of the arranging of letters the people are diffrent so there can be many ways by permutation.
Nirmal said:
1 decade ago
(7C2 x 3C1) = 7 x 6 x 3
How it happened explain please?
How it happened explain please?
BGT said:
1 decade ago
How can't we use any other e example?
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