Question

There are 12 students in a social studies class. three students will be selected to present their term projects today. in how many different orders can three students be selected? 1,320 220 504 36

Answer 1

As, If the order is important then we use permutation;

total no. of students= 12
selected students= 3

12P3= 12!/(12-3)!=1320

Answer 2

The correct answer is:

1320.

Explanation:

This is a permutation of n objects taken r at a time.

In this case, n is 12 and r is 3.

The formula is:

$P_r^n=\frac{n!}{(n-r)!} \\ \\=P_3^{12}=\frac{12!}{(12-3)!} \\ \\=\frac{12!}{9!} = 1320$