=> (6%) Problem 13: The current in a simple single resistor circuit is / = 6.75 A. A second resistor, with resistance R = 79 Q2, is added in series with the first and the current drops to 12-3.2 A. 33% Part (a) Enter an expression for the resistance, R, of the first resistor. 33% Part (b) Calculate the resistance, in ohms. 33% Part (c) Enter an expression for the resistance R in terms of I2, R, and the voltage of the source, V.