Question

Ten students need to present their reports. Five can present each day. How many ways can the teacher choose a group of five students to present their reports on the first day?
How many ways can the teacher choose a group of 5 students to present on the first day if Marjorie must present on the first day?

Answer 1

Solution:

There are a total of 10 student.

when Teacher is supposed to choose 5 Students randomly from the group of 10.

The selection can be done in$=10_C_{5} \ \ ways$

$\\\\=10_C_{5}=\frac{10!}{5!5!} \\\\=252 \ \ ways.$

when Teacher is supposed to choose 5 Students randomly from the group of 10, if Marjorie must present on the first day.

The number of ways$9_C_{4}=\frac{9!}{4!5!}=126$

Answer 2

Answer:

For the first one: 252

For the second one: 126

Step-by-step explanation:

:)