From a class of 28 students, how many different ways can 4 students be selected to serve on the student council as president, vice president, secretary and treasurer?

1 Answer
Feb 6, 2016

Here, order matters, so we will use the permutation formula


Assuming P represents the number of permutations possible.

#P =(n!)/((n - r)!)#

#P = (28!)/((28 - 4)!)#

#P = 491 400#

There are 491 400 ways of picking the 4 positions.

Practice Exercises:

  1. An earthquake preperation team must be selected. Two engineers, three construction workers and two urban planners have to be picked from a group of 9 engineers, 16 construction workers and 10 urban planners. Find the total number of ways the comittee can be selected.