Question

Nine new employees, two of whom are married to each other, are to be assigned nine desks that are lined up in a row. If the assignment of employees to desks is made randomly, what is the probability that the married couple will have nonadjacent desks

Answer 1

P = 0,88 or P = 88 %

Explanation:

The probability of having a married couple in nonadjacent desks is the total number of probabilities minus the probabilities of having them in adjacent places divide by total number of outcomes

The total possibilities (outcomes) of 9 elements in a row is:

P(₉) = 9!

P(₉) = 9*8*7*6*5*4*3*2*1

P(₉) = 362880

And the outcomes in which they are adjacent to each other is:

We consider them as one unit them we in this situation have 8 elements

P(₈) = 8!

P(₈) = 8*7*6*5*4*3*2*1

P(₈) = 40320

Then the probability that the married couple will have nonadjacent desks is:

P = P(₉) - P(₈) / P(₉)

P = 362880 - 40320 / 362880

P = 322560/ 362880

P = 0,88 or P = 88 %