Why we use permutation concept instead of combination.

Manasa said:
(Tue, Jun 14, 2011 07:25:39 AM)

@Gayathri

In this case we are not selecting any letters. Just we are arranging the letters according to given condition.

Kesav said:
(Thu, Jul 21, 2011 07:57:15 PM)

Can any one solve this problem for me?

1! + 2! + .... + 50!=?

a) 3.1035*10^64
b) 2.1021*10^65
c) 3.1035*10^63
d) 3.1035*10^62

Riddhi said:
(Sun, Jul 24, 2011 12:56:19 AM)

@kesav:plz give me ans. Is it b?

Vishnu said:
(Sun, Aug 14, 2011 08:57:33 PM)

It is asked in TCS apti test.

Gautam said:
(Wed, Dec 28, 2011 05:59:07 PM)

There are 6 letters in the given word, out of which there are 3 vowels and 3 consonants.

Number of ways of arranging the vowels = nPr= n!/(n-r)= 3/(3-3)
=3!/0! ,=3*2*1= 6 {we define 0! = 1}

Also, the 3 consonants can be arranged at the remaining 3 positions.

Number of ways of arranging the vowels = nPr= n!/(n-r)= 3/(3-3)
=3!/0! ,=3*2*1= 6 {we define 0! = 1}.

Total number of ways = (6 x 6) = 36.

Nikhil said:
(Wed, Jan 30, 2013 09:48:32 AM)

Vowel can even be put at the 7th place, not considered above, which will increase the number of possible arrangements. Please clarify?

Athu said:
(Thu, Apr 11, 2013 02:49:17 AM)

What is odd positions?

Drushya said:
(Sat, Apr 20, 2013 05:30:13 PM)

@Athu.

Odd position means its like odd no.

For example : 1 2 3 4 5 6.

In this case odd position is :1 3 5 & even position : 2 4 6.

Jinal said:
(Sun, Jul 28, 2013 12:59:51 PM)

Vowels can also take position 7 (the last position) ?

V C V C V C V.

So the answer would be 3!*4C3 = 24.

Is this correct?

Vasudha said:
(Wed, Jul 31, 2013 11:31:50 PM)

Since there is nothing mentioned about repetitions so the no ways could also be 3*3*3(i.e., E can come in all three odd places and same goes for the other two vowels A and I as well) for the three odd positions of vowels.

And similarly the other three letters can be arranged so the answer should be 3*3*3*3*3*3.

Sanjay said:
(Sun, Sep 1, 2013 07:54:50 PM)

Hi guys.

There is 3 odd, 3 even place and the word have 3 vowel and 3consonant. We arrenge 3 vowel in 3 odd place and 3 consonant in 3 rest place such that VCVCVC So total no of way = 3p3*3p3 = 36.

Neha Pant said:
(Sun, Aug 17, 2014 03:26:51 PM)

But here it is not mentioned that repetition is allowed so according to me the correct way is,

3*3*3*3*3*3 = 729 which is not in option.
3*3*3 for 3 vowels and other for consonant .

Please explain it?

Nee said:
(Thu, Oct 16, 2014 02:27:05 AM)

Can't we do it in this way like first we find all possible ways of arranging all letters.

i.e 6! and then subtract 4!(3!) from 6! to get the answer.