1)18 21/53 * 27/34 * 42 2/5 * 47 2/9=(975*27*212*425)/(53*34*5*9)=(975*3*4*25)/(1*2*5*1)=(975*3*2*5)/(1*1*1*1)=29250
2)125/161 * 8 216/617 * 15 17/40 * 22 31/36
=
(125*5152*617*823)/(161*617*40*36)=(125*32*1*823)/(1*1*40*36)=
=(125*4*1*823)/(1*1*5*36)=(25*1*1*823)/(1*1*1*9)=20575/9=2286 1/9
3)29250- 2286 1/9=26963 8/9