Determining maximum memory size, maximum unique operations, and maximum value of an unsigned constant for 12 bit instruction microprocessor

Question

I'm new to computer architecture and am having some trouble with this question: A hypothetical microprocessor having 12-bit instructions is composed of three fields: the first 4 bits are reserved for the opcode, the next two bits are reserved for a register number and the remaining bits contain the operand memory. What is the maximum memory size, maximum number of different operations the system would be able to understand and the maximum value of an unsigned integer?

Answer 1

There’s not enough information to answer that question. You provided specs about the instructions but not about address size or data word size. The only thing we can say for sure is that 4 bits are enough to specify 16 different instructions.