Jawabanmu

2014-08-22T18:42:42+07:00
Selisih angka 3-1 = 2 , 6-3 = 3 , 10-6 =4,.........
selisih angka depan 2-1 = 1, 4-2= 2, 7-4 = 3,......
jadi ke 12 =67 68 69 70 71 72 73 74 75 76 77 78
3 3 3