19.2

To start we need to consolidate this circuit.

Follow the steps shown below

Step One: Combine 11 ohms and 13 ohms

To combine the two resistors... [(11^-1)+(13^-1)]^-1
the combined resistors equal 5.958 ohms and should be stored in alpha A

Step Two: Combine 3 ohms and A (5.958 ohms).

To combine the two resistors... 3+A
the combined resistors equal 8.958 ohms and should be stored in alpha B

Step Three: Combine 15 ohms and B (8.958 ohms).

To combine the two resistors... [(15^-1)+(B^-1)]^-1
the combined resistors equal 5.60869 ohms and should be stored in alpha C