A student committee on academic integrity has 30 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 choices
A) 7
B) 8
C) 9
D) 6
E) 11
xC1 * (x-1)C1=30   x^2 -x -30 =0   (X-6) (X+5) = 0   X= 6 , -5   -5 can't possible.   6
<result>D</result>
A student committee on academic integrity has 30 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?