= The booking limits for four fare classes in a flight are given as b = b2 (61, 62, 63, 64) = (15, 10,5,2). (a) What is the available capacity for these four classes, i.e., what is the booking limit for classes {1, 2, 3, 4]? [Select ] (b) From this available capacity, how many seats are protected for class 1, i.e., what is the protection level for class 1? [Select ]