(1)10,12,12,18,()162
a24 b30 c36 d42
(2)4, 2, 3, 4, 19,( )
A.196 B, 246 C. 286 D,316
(3)7/3,21/5,49/8,131/13,337/21,( )
A.885/34;B.887/34;C.887/33;D.889/3
(4)150,75,50,37.5,30,( )
A .20 B. 22.5 C.25 D .27.5
(5)77,49,28,16,12,2,( )
A. 10 B. 20 C. 36 D. 45