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

For the first one: 252

For the second one: 126

Explanation:

:)

Answer 2

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)=(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)=(9!)/(4!5!)=126`