1. The problem statement, all variables and given/known data Two 1.50 V batteries-with their positive terminals in the same direction-are inserted in series into the barrel of a flashlight. One battery has an internal resistance of 0.255 ohms, the other has a resistance of 0.153 ohms. When the switch is closed, a current of 600 mA occurs in the lamp. (a) What's the lamps resistance? (b) What fraction of the chemical energy transformed appears as internal energy in the batteries? 2. Relevant equations 3. The attempt at a solution I'm not sure how to start the problem. Please Help.