So the answers are already there, starting when it mentions the number of OP Codes. I sort of understand how they got mem range and data range but not entirey. I need somebody to explain how we got all four of those answers though.

5.Calculate the following parameters of a hypothetical computer system with these features: a) Hexadecimal notation; b) IR- OPCode + Mem Addr; c) IR- three Hex digits; d) PC- two Hex digits; and e) Data IR (unsigned integer). (10 points) Number of different OPCodes: 16 Mem size in bits: 28 positions * 12 bits / positions Mem range: 00-FF Data range: 000-FFF