|
|
16 . 36,12,30,36,51,( )
A:69;
B:70;
C:71;
D:72
答案:选A,36/2=30-12;12/2=36-30;30/2=51-36;36/2=X-51;X=69=>选A
17 . 1,7,8, 57, ( )
A:123;
B:122;
C:121;
D:120;
答案:答案C,12+7=8,72+8=57,82+57=121
18 . 5,10,26,65,145,( )
A:197;
B:226;
C:257;
D:290;
答案:选D,思路一:5=22+1,10=32+1,26=52+1,65=82+1,145=122+1,290=172+1,思路二:三级等差
19 . 5,10,26,65,145,( )
A:197;
B:226;
C:257;
D:290;
答案:答案D
,5=22+1,10=32+1,26=52+1,65=82+1,145=122+1,290=172+1,其中2,3,5,8,12,17二级等差。
20 . 0,1,3,8,22,63,( )
A:121;
B:125;
C:169;
D:185
答案:选D,1×3-0=3;3×3-1=8;8×3-2=22;22×3-3=63;63×3-4=185 |
|