(3/14)*(7/9)=(3*7)/(14*9)=1/6
(3/14)*(2/7)=(3*2)/(14*7)=6/98=3/49
(12/18)*(2/3)=(12*2)/(18*3)=24/54=4/9
(4/9)*(16/27)=(4*16)/(9*27)=64/243
6=6/1
18=18/1
21=21/1
d=d/1