Theory 

Conversion Rule (Gray → Binary)

1. MSB Rule:
   The most significant bit (MSB) of Binary is the same as the MSB of Gray.
   Bn​=Gn​

2. Other Bits Rule:
   Each next Binary bit is obtained by XOR of the previous Binary bit with the current Gray bit.
   Bi​=Bi+1​⊕Gi​

Truth table 

K-Map

Boolean expression 

Logic Circuit