arpitkansal wrote:

chetan2uI don't understand why the groups are identical.The students are not identical so how can the groups be identical?

In such questions do we have to presume the groups as same identity and ignore the diversity of students?

Hi..

The reason is that we have not named the group..

So if A,B are in group I, C,D are in group 2 and E,F are in group 3..

It will be same when A,B are in group I, C,D are in group 3 and E,F are in group 2..

OR if A,B are in group 2, C,D are in group 1, and E,F are in group 3..

Since here all groups name and size wise are identical, all above distribution are identical, and hence we divide by 3!

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1) Absolute modulus : http://gmatclub.com/forum/absolute-modulus-a-better-understanding-210849.html#p1622372

2)Combination of similar and dissimilar things : http://gmatclub.com/forum/topic215915.html

3) effects of arithmetic operations : https://gmatclub.com/forum/effects-of-arithmetic-operations-on-fractions-269413.html

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