61.  Direction: Which one set of letters when sequentially placed at the gaps in the given letters series shall complete . _aa_ba_bb_ab_aab

62.  2/3, 4/7, 7/13, 11/21, ?

63.  1, 9, 25, ?, 81

64.  1, 3, 7, 13, 21, 31, 43, ?

65.  Direction: In each of the following questions, a series is given, with one/two terms missing. Choose the correct alternatives from the given ones that will complete the series. 6,8 : : 2, 12 : : 5, 9 : : 4, ?_

66.  14, 21, 30,41,54, ?

67.  AZBY, CXDW, EVFU, ?

68.  264, 396, 473, 583, ?

69.  15, 23, 31, 39, ?, 54, 61

70.  A, Z, B, Y, C, X, ?, ?

71.  365, 364, 355, 330, 281, ?

72.  Direction: Which one set of letters when sequentially placed at the gaps in the given letters series shall complete . m_ _ I m I _ m m_ l

73.  Direction: Which one set of letters when sequentially placed at the gaps in the given letters series shall complete . bb_aab_caab_ca_

74.  Direction: Which one set of letters when sequentially placed at the gaps in the given letters series shall complete . -wi -- w-nt -in- wi-

75.  121, ?, 169, 196,225