PnC
for first case it is same as mine but for second case ,i did
7C5 to select 5 members from Y , then 5! to map those 5 members , then the remaming 2 have 5 x5
so 7C5 x 5! x5 x 5 but i am not getting ans
7 Replies
@Apu
Note for OP
+solved @user1 @user2... to close the thread when your doubt is solved. Mention the users who helped you solve the doubt. This will be added to their stats.This leads to overcounting no?
how?
For instance, say, 1,2,3,4 and 5 from Y are mapped to 1,2,3,4,5 in X; then 6 and 7 are mapped to say, 1 and 2. And another case, where 6,2,3,4 and 5 are mapped to 1,2,3,4,5 and 7 and 1 are mapped to 2 and 1. Both the cases are same, but are counted separately by your solving.
ooh
ic
how can i stop these mistakes? i end overcounting alot
Taking small examples definitely helps.
(Examples as in if we select this because of this and this gets mapped to that and so on)