Question

A committee must be formed with 5 teachers and 4 students. If there are 6 teachers to choose from, and 15 students, how many different ways could the committee be mad?

Answer 1

Answer:

8190 ways

Step-by-step explanation:

Given

$Teachers = 6$

$Students = 15$

Selection

$Students = 4$

$Teachers = 5$

Required

Number of ways of selection

4 students can be selected from 15 students in:

$Students= ^{15}C_4$

Similarly.

5 teachers can be selected from 6 teachers in:

$Teachers= ^{6}C_5$

So, the required number of selection is:

$Selection = ^{15}C_4 * ^6C_5$

Apply combination formula:

$Selection = \frac{15!}{(15-4)!4!} * \frac{6!}{(6-5)!5!}$

$Selection = \frac{15!}{11!4!} * \frac{6!}{1!5!}$

$Selection = \frac{15*14*13*12*11!}{11!*4*3*2*1} * \frac{6*5!}{1*5!}$

$Selection = \frac{15*14*13*12}{4*3*2*1} * \frac{6}{1}$

$Selection = \frac{32760}{24} * 6$

$Selection = 1365 * 6$

$Selection = 8190$