A student committee on academic integrity has 72 ways to select a president and vice president from a group of candidates. The same person cannot be both president and vice president. How many candidates are there?
Choose the correct choice from the following:
A) 7  B) 8  C) 9  D) 10  E) 11
xC1 * (x-1)C1=72   x^2 -x -72 =0   (X-9) (X+8) = 0   X= 9 , -8   -8 can't possible.   9
<result>C</result>
A student committee on academic integrity has 72 ways to select a president and vice president from a group of candidates. The same person cannot be both president and vice president. How many candidates are there?