Two couples and one single person are seated at random in a row of five chairs. What is the probability that neither of the couples sits together in adjacent chairs?
I know sample space is 120 (5!) and hence the denominator. What do we manipulate to get the numerator, given the info. above?
Outcomes one couple is sitting together: 4!*2
Outcomes the other couple is sitting together: 4!*2
Outcomes that both couples are sitting together: 3!*2*2
Outcomes neither couples are sitting together