Aptitude - Permutation and Combination - Discussion
Discussion Forum : Permutation and Combination - General Questions (Q.No. 8)
8.
In how many ways a committee, consisting of 5 men and 6 women can be formed from 8 men and 10 women?
Answer: Option
Explanation:
| Required number of ways | = (8C5 x 10C6) | |||||||
| = (8C3 x 10C4) | ||||||||
|
||||||||
| = 11760. |
Discussion:
61 comments Page 5 of 7.
Younisali.syed said:
1 decade ago
I agree with this answer but when you see question no: 4 in that he selected and then arranged in this problem he only selected.
Any one tell me why so?
Any one tell me why so?
Vimala said:
1 decade ago
No need to multiply with 11! because they did not ask for the arrangement of the person. We need to concentrate only on the selection of person for the committee.
Shuhaib said:
1 decade ago
Another method.
In unit place we can fix only one number ie 5. Other place we can selected 6c2. So answer is 6c2*1.
In unit place we can fix only one number ie 5. Other place we can selected 6c2. So answer is 6c2*1.
RockstR said:
1 decade ago
Why are we not multiplying with 11! ? these 5 men and 6 women can also be arranged within themselves. Right?
Manu said:
1 decade ago
Yes, If you do it with (nCr = nC (n-r) ) then also we are getting the same answer. Please don't get confuse.
Diwakar said:
1 decade ago
Formula: n!/r!(n-r)!
8C5 = 8!/5!(8-5) which is 6*7*8/1*2*3 = 56
10C6 = 10!/6!(10-6)! which is 7*8*9*10/1*2*3*4 = 210
Therefore: 56*210 = 11760
8C5 = 8!/5!(8-5) which is 6*7*8/1*2*3 = 56
10C6 = 10!/6!(10-6)! which is 7*8*9*10/1*2*3*4 = 210
Therefore: 56*210 = 11760
Senorita said:
1 decade ago
As per my knowledge d calculation above shows only selection part. Aren't we suppose to calculate the number of ways it can b arranged into? in this case 11! ?
JOE said:
1 decade ago
Actually the formula for combination is nCr = nC(n-r).
Therefore 8C5 = 8C(8-5) = 8C3.
the answers will come the same , simply it will make the problem easier
If the combination e.g is 11C4 then = 11C(11-4) = 11C7 it will also come the same answers with 11C4...
Therefore 8C5 = 8C(8-5) = 8C3.
the answers will come the same , simply it will make the problem easier
If the combination e.g is 11C4 then = 11C(11-4) = 11C7 it will also come the same answers with 11C4...
Priyadarshini said:
1 decade ago
nCr=nC(n-r) is used for simplification purpose.
We can also calculate it directly as nCr.
Answer will be same in both ways.
We can also calculate it directly as nCr.
Answer will be same in both ways.
Sunita said:
1 decade ago
Its for simplicity you can do it by solving first step also.
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