How do you evaluate 11C4?

1 Answer
Jun 29, 2017

#330#

Explanation:

#"using the definition of the "color(blue)"binomial coefficient"#

#• color(white)(xx) ^nC_r=(n!)/(r!(n-r)!)#

#"where " n! =n(n-1)(n-2)........xx1#

#"here " n=11" and " r=4#

#rArr^(11)C_4=(11!)/(4!7!)#

#color(blue)"cancel 7! from numerator/denominator"#

#=(11xx10xx9xx8)/(4xx3xx2xx1)#

#=330#