Solution :
Let the three places be 1, 2, 3, 4, 5, 6, 7, 8
a). Number of the cases when a general manager is the next to a vice president is equal to 7 and the these 2 can be arranged in 21 ways. So the total number of ways = 7 x 2
= 14
[(1,2)(2,1) (2,3)(3,2) (3,4)(4,3) (4,5)(5,4) (5,6)(6,5) (6,7)(7,8) (8,7)(7,6)]
Therefore the required probability is

= 
b). The probability that the marketing director to be placed in the leftmost position is


c). The two events are not independent because


where A is the case a and B is the case b.