A student committee on academic integrity has 56 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 most appropriate option:  A) 7  B) 8  C) 9  D) 10  E) 11
xC1 * (x-1)C1=56   x^2 -x -56 =0   (X-8) (X+7) = 0   X= 8 , -7   -7 can't possible.   Hence 8 should be the answer   8
<result>B</result>
A student committee on academic integrity has 56 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?