Problema Solution
The receptionist at a dental office has only 4 appointment times available before Thursday and 8 patients have toothaches
In how many ways can the receptionist fill those appointments?
Answer provided by our tutors
we need to find the number of 4-combinations of the set with 8 elements (the set of patients)
C(8, 4) = 8!/(4!(8 - 4)!) = (2*3*4*5*6*7*8)/(2*3*4*2*3*4) = 70
by definition n! = 1*2*3*..*(n-1)*n
the receptionist can fill the appointments is 70 ways.