Question

67.54.46.35.29.( )括号里应该填什么？什么规律？

Answer 1

67. 54. 46. 35. 29 .(20 )
67-13=54
54-8=46
46-11=35
35-6=29
29-9=20
规律：前一个数 -13，-8，-11，-6，（-9）

Answer 2

67 -54 =13 ; 54 -46 = 8 ; 13 - 8 = 5
54 -46 = 8 ; 46 - 35 = 11 ; 8 -11 = -3
46 - 35 = 11 ; 35 - 29 = 6 ; 11 -6 = 5
6 - ? = -3
?=6 3 =9
29 -9 = (20)
则答案是20