Answer:
Opcode = 3
Mode =2
RegisterRegister =7
AR = 20
Explanation:
a) Number of addressing modes = 4 = 22 , So it needs 2 bits for 4 values
Number of registers = 65 = 1000001 in binary , So it needs 7 bits
AR = 20
Bits left for opcode = 32 -(2+7+20) = 3