Chapter 13.9, Problem 22PPS

To determine

To Find: Given situation is permutation or combination.

Answer to Problem 22PPS

The possible number of different rankings is $120$ .

Explanation of Solution

Given information:

Phone survey is carried out:

  

Calculation:

Let’s, consider the activities as the music, sports, weather and news and entertainment.

There are $5$ activities which are listening on the radio.

The order is prioritized so here permutation is used.

There are $5$ activities.

Number of activities calculated as,

  $\begin{array}{l}P\left(5,5\right)=\frac{5!}{\left(5-5\right)!}\\ =\frac{5\times 4\times 3\times 2\times 1}{0!}\\ =5\times 4\times 3\times 2\times 1\\ =120\end{array}$