Question 722523
Think of Grace and Joey as one person that take up one "seat" since they cannot be separated. So you really have 14 - 2 + 1 = 13 people.


There are 13! = 13*12*11*10*9*8*7*6*5*4*3*2*1 = 6,227,020,800 ways to arrange the 13 people


Double this to get 2*6,227,020,800 = 12,454,041,600 ways total


Note: you double it because there are 2 ways to arrange Grace and Joey