Respuesta :
all possibilities = 9!
possibilities that harry sits at an end = 8! + 8!
possibilities that harry doesn't sit at an end = 9! - 8! -8!
possibilities that harry sits at an end = 8! + 8!
possibilities that harry doesn't sit at an end = 9! - 8! -8!
List of all possibilities, without restrictions (ie Harry can sit in any of the 9 seats): [tex]9![/tex]
List of all possibilities where Harry sits on either end: [tex]2 \cdot 8![/tex]
Hence, list of all possibilities where Harry doesn't sit on either end: [tex]9! - 2 \cdot 8! = 282,240[/tex] ways.
List of all possibilities where Harry sits on either end: [tex]2 \cdot 8![/tex]
Hence, list of all possibilities where Harry doesn't sit on either end: [tex]9! - 2 \cdot 8! = 282,240[/tex] ways.
