rite2mythili wrote:

I apprached this probem as (12 ways to select a previous exp. person)*(9 ways to select 1 person from 9)*(8 ways to select 1 person from remaining 8) ==> 12*9*8 = 864. But from the answer, I see that it has to be divided by 2, but there is no repetition in picking up from 8p after having picked up from 9p.

Can you please let me know what the flaw in my approach is.

I understand the 12C1 * 9C2 approach, wanted to understand this.

Thanks!

(9 ways to select 1 person from 9)*(8 ways to select 1 person from remaining 8) In this way you count the choices (A,B) and (B,A) separately. The pair A and B should be counted only once, because all that matters, is that both are not experienced, not who they are or in what order they were chosen.

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