Here's the question you clicked on:
virtus
find the no. of ways in which 8 people can be seated at 2 round tables with 4 people sitting at each table?
acually its like ... choose four people ...then arrange them .... permutaion means choosing and aranging
that dot means multiplty
why does the answer in my solution book say this : 7x6x5x3x2x1x2
wait a sec .... let me take a look at question again
@hba having epiphanies are we?
IF UR ASKED OF A ROW THEN n! IF UR ASKED ABOUT A CIRCLE OR ROUND ITS (n-1)! AND IF ITS A NECKLACE OR GARLAND ITS 1/2(n-1)!
IN UR CASE IT WOULD BE (8-1)! =7!
AND 2 TABLES SO U MULTIPLY IT BY 2 THEN
Remember that a circular permutation is (n – 1)! Break the seating process into "activities" like this: 1) Choose the people who are seated at each table. C(8,4 = 8•7•6•5/4•3•2•1 = 70). When you choose for 1 table the other four automatically go to the other table. 2) Arrange the 4 people at table A: (4 – 1)! = 3! = 6 3) Arrange the 4 people at table B. Also 3! =6 So answer is C(8,4)•3!•3! = 70•6•6 = 2520
he copied it from somewhere :D
anyway ... nice work @hba :D
You are free: to Share — to copy, distribute and transmit the work to Remix — to adapt the work
hey @hba so you used combinations and not only permutations for this questions?