probability q - is the answer wrong

[anonymoushehe]

Am I being stupid, for the last part shouldn’t you consider the fourth and fifth people? So u consider the cases where either one of them participate/don’t participate or both but make sure the first plays, and the second and third don’t?

 

[jasn9776]

Hello,
you could consider each case for the fourth and fifth people, and sum up each case, but that would be the same as just not considering the fourth and fifth people. When you don't consider each case separately, it is equivalent to considering all cases.