1) (11/18*2/7)*1 7/11=
=11/63*1 7/11=11/63*18/11=18/63
2) (3/8*9/11)*1 2/9=
=27/88*11/9=3/8
3) 3 2/3*(3/4*3/8)*1 1/3=11/3*9/32*4/3=
=33/32*4/3=11/8=1 3/8
4) 0,6*(2,1*1 2/3)=6/10*(2 1/10*1 2/3)=
=3/5*(21/10*5/3)=3/5*7/2=21/10=2 1/10
5) (5,7*2,5)*2/5=14,25*0,4=5,7
6) 3,1*(7/15*10/31)*2 1/7=
=3 1/10*14/93*15/7=31/10*14/93*15/7=
=7/15*15/7=1