Question

if there are 20 students in a 5th grade class. Four of these students will be selected to be patrols. In how many ways can the four patrols be selected?

Answer 1

Answer:

There are 4845 ways to select four patrols

Step-by-step explanation:

Total number of students in 5 th grade = 20

No. of students selected for patrols = 4

We are supposed to find In how many ways can the four patrols be selected

We will use combination

Formula : $^nC_r=\frac{n!}{r!(n-r)!}$

Substitute n = 20 and r = 4

So,the four patrols can be selected in no. of ways = $\frac{20!}{4!(20-4)!}=4845$

Hence There are 4845 ways to select four patrols