tolong Yg a, b,c,d bantu pake cara

a) 2, 10, 50, 250, 1250, 6250, 31250, ...
b) 192, 96, 48, 24, 12, 6, 3, ...
c) 164, 172, 180, 188, 196, 204, 212, ...
d) 3/4, 1, 4/3, 16/9, 64/27, 256/81, 1024/243, ...