Can someone help explain this to me

In class, we discussed how to write assembly language code to calculate A B + C with systems requiring various numbers of operands. You can also find this discussion repeated on page 117 of your book. Assume that a zero- operand microprocessor takes 35ns to fetch, decode and execute one instruction; a one-operand microprocessor takes 50ns, a two-operand microprocessor takes 70ns, and a three-operand microprocessor takes 100ns. Which microprocessor calculates calculates and stores a value in A the fastest? In class, we discussed how to write assembly language code to calculate A B + C with systems requiring various numbers of operands. You can also find this discussion repeated on page 117 of your book. Assume that a zero- operand microprocessor takes 35ns to fetch, decode and execute one instruction; a one-operand microprocessor takes 50ns, a two-operand microprocessor takes 70ns, and a three-operand microprocessor takes 100ns. Which microprocessor calculates calculates and stores a value in A the fastest