24 bits word
word contains opcode bits + address bits.
Instructions set contain 150 different operations so to identify each uniquely would require at least 8 bits (2^8=256).
so 16 bits left for address. So for question no 1 Ans is B
16-bit for address so total memory that can be addressable is 2^16.
word size is 24 bit so largest unsigned binary number is 2^24 - 1.
So for question no 2 Ans is C