Question

Mrs lunette has 18 students in her class. She wants to send 3 of these students to pick up book for the class. How many combinations of 3 students can she choose?

Answer 1

Answer:

Mrs Lunette can choose 816 combinations of 3 students.

Step-by-step explanation:

We can use the combination formula to find the number of combinations Mrs Lunette has,

Number of combinations = $\frac{n!}{k!(n-k)!}$

Where,

$n$ is the total number of students.

$k$ is how many students can be chosen at a time.

Now we can substitute the values to the above equation,

Number of combinations = $\frac{18!}{3!(18-3)!}$

=$\frac{18!}{3!(15)!}$

=$\frac{18*17*16}{3!}$

=$\frac{18*17*16}{3*2*1}$

=$\frac{3*17*16}{1}$

=$816$

Mrs Lunette can choose 816 combinations of 3 students.