Suppose that a book will be selected at random from these 91 novels.

P(Detective  )   =  [ 12 + 20 ] / 91   = .35

P(Hardcover) = [ 12 + 8 + 9 ] /91  = .32

P (Paperback Detective)  = 20 / 91 = .22

P ( Paperback or Detective )  =  [  62 + 32 - 20 ] / 91  = .59

P(Not a Detective)  = [91 - 32 ] / 91  = .65