a)
[tex]a=4 \ dm\\\\b=2,5 \ dm\\\\c=3 \ dm\\\\V=4\cdot2,5\cdot3=10\cdot3=30 \ dm^3=\boxed{30 \ l}=\boxed{30 \ 000 \ ml}[/tex]
b)
[tex]a=50 \ cm=5 \ dm\\\\b=30 \ cm=3 \ dm\\\\c=80 \ cm=8 \ dm\\\\V=5\cdot3\cdot8=40\cdot3=120 \ dm^3=\boxed{120 \ l}=\boxed{120 \ 000 \ ml}[/tex]
c)
[tex]a=3,5 \ dm\\\\b=85 \ cm=8,5 \ dm\\\\c=40 \ cm=4 \ dm\\\\V=3,5\cdot8,5\cdot4=14\cdot8,5=119 \ dm^3=\boxed{119 \ l}=\boxed{119 \ 000 \ ml}[/tex]
d)
[tex]a=1 \ m=10 \ dm\\\\b=1 \ dm\\\\c=1 \ cm=0,1 \ dm\\\\V=10\cdot1\cdot0,1=1\cdot1=1 \ dm^3=\boxed{1 \ l}=\boxed{1000 \ ml}[/tex]