There are 6 contestants for the post of chairman secretary and treasurer. These positions can be filled by any of the 6. Find the possible no. of ways whether the 3 positions may be filled.
Solution
Chairman Secretary Treasurer
6 5 4
Hence the no of ways of filing the three positions is 6 x 5 x 4 = 120
^{6}P_{3} = (6!)/((6 - 3)! )
= (6 * 5 * 4 * 3 * 2 * 1) /(3 * 2 * 1)
= 720/6
= 120