4. D 0=x`y`z` D 1=x`y`z D 2=x`y z` D 3=x`y z D 4=x y` z` D 7=x y z D 6=x y z` D 5=x y` z z y D 0 x inverter x y z xyz 1 1 1 1 AND 3-to-8 line decoder circuit
5.
6.
7. D 0 D 1 D 2 D 3 D 4 D 5 D 6 D 7 X=D4+D5+D6+D7 y=D2+D3+D6+D7 z=D1+D3+D5+D7 Octal to binary encoder x y z x+y+z o o o 0 1 0 0 1 OR