[Math] Placing beads on a necklace, 7 colours. How many can be made

discrete mathematicsprobability

Dude wants to make a necklace with 7 beads, each a diffrent color.
(red, orange, yellow, blue, green, indigo, violet) placed on a chain that is then closed
to form a circle. How many different necklaces can he make?

(Since the beads can slide
along the chain, the necklace with beads R O Y G B I V would be considered the same
as O Y G B I V R for example

So im assuming that the fact its a chain doesnt matter at all does it? It would be 7! = 5040 diffrent necklaces.

Is that correct?

Best Answer

Since it doesn't matter where you place the first bead, the number of ways of arranging the other beads = $6!$

But considering the fact that the beads doesn't have a differentiation between left/right, the final answer would be: $$\dfrac{6!}{2}$$