What is C(7,3)?

1 Answer
Feb 26, 2017

Answer:

35

Explanation:

I am pretty sure you are referring to combinatorics and specifically the combination # C_3^7#, aka #7# choose #3#, often written as #((7),(3))#.

Well:

#((n),(k)) = (n!)/((n-k)!k!)#

Which means that:

#((7),(3)) = (7!)/(4!3!)#

#= (color(red)(1 times 2 times 3 times 4) times 5 times color(blue)(6) times 7)/((color(red)(1 times 2 times 3 times 4) )(color(blue)(1 times 2 times 3)))#

#= 35#