The Number of Ways to Arrange X Successes Among N $\frac { n ! } { x ! ( n - x ) ! }$

Multiple Choice

The number of ways to arrange x successes among n trials is equal to

A) $\frac { n ! } { x ! ( n - x ) ! }$
B) $\frac { n ! } { ( n - x ) ! }$
C) $n / x$
D) $n ! /x!$