A 9.4 resistor and a 6.3 resistor are connected in series with a power supply.
a) The voltage drop across the 6.3 resistor is measured to be 13 V. Find the voltage output of the power supply.
b) The two resistors are connected in parallel across a power supply, and the current through the 9.4 resistor is found to be 0.25 A. Find the voltage setting of the power supply.