Question

In how.many ways 5 boys be seated in a row if two of them refused to sit together?

Answer 1

@iGreen help

Answer 2

@mathmate help

Answer 3

@misty1212 can u help?

Answer 4

do you have choices

Answer 5

No @Miss.Sweetie.Pee

Answer 6

give me a min

Answer 7

Ok i m waitin :)

Answer 8

Start with 5 boys.
We have 5 choices for the first seat, 4 choices for the second, ... for a total of 5! = 120 ways.

Now for the two boys in question, we need to know, how many of the 120 cases are they together. If we put them together as one unit, then there are 4 choices for the first seat, 3 for second, ... for a total of 4! where they are together.

The difference between the two numbers will give the number of ways the do \(not\) sit together.