Chapter 8.5, Problem 68E

To determine

To find: the number of combinations of seven paralegals with two years of experience and three paralegals with one year of experience are possible.

Answer to Problem 68E

Numbers of ways to selection of 10 paralegals is 1956240.

Explanation of Solution

Given Information:

A law office interviews paralegals for 10 opening. There are 13 paralegals with two years of experience and 20 paralegals with one year of experience.

Calculation:

Seven of thirteen paralegals with two years of experience mean

  $\begin{array}{c}{}_{13}{C}_7=\frac{13!}{\left(13-7\right)!7!}\\ =1716\end{array}$

Three of twenty paralegals with one year of experience mean

  $\begin{array}{c}{}_{20}{C}_3=\frac{20!}{\left(20-3\right)!3!}\\ =1140\end{array}$

Numbers of ways to selection of 10 paralegals can be calculated as

  $\begin{array}{c}{}_{13}{C}_7{\times }_{20}{C}_3=1716\times 1140\\ =1956240\end{array}$