Robertwellson
New member
- Joined
- Jun 11, 2020
- Messages
- 22
For 13a iii the answer is 7257600.
Why isn't the equation is 11p 11 * 2!
But instead is 10p10 * 2! Why?
Can someone please explain this permutations and combination question?
- Thread starter Robertwellson
- Start date
For 13a iii the answer is 7257600.
Why isn't the equation is 11p 11 * 2!
But instead is 10p10 * 2! Why?
Dr.Peterson
Elite Member
- Joined
- Nov 12, 2017
- Messages
- 16,087
The one special couple consists of two people, so there are 10 others. The couple can be seated in 2! ways, and the remaining 10 (not 11) people can be seated in 10! ways.
Robertwellson
New member
- Joined
- Jun 11, 2020
- Messages
- 22
Oh I see it now, much appreciated.
because we are not changing the seat 1and 2 with the others