Question

Charlene has nine different necklaces, and she wears four at a time. How many different ways can Charlene wear four necklaces?

Answer 1

\[\dbinom{9}{4}\]

Answer 2

compute via
\[\frac{9\times 8\times 7\times 6}{4\times 3\times 2}\]
\[=9\times 2\times 7=216\]

Answer 3

or if you have a nice calculator use
\[9C4\]

Answer 4

thanks again :)