Question

There were 4 chairs in a row and 7 students. How many ways could the students
occupy the 4 chairs if 4 students sat down every time?​

Answer 1

Answer:

Total chairs =7

To select 4 conservative chairs,

No. of ways =7−4+1

(n−r+1)

=4

To arrange 4 students at these 4 chairs

No. of ways =4!

⇒ Total No. of arrangements =4×4!