1. The problem statement, all variables and given/known data What is the combined resistance when the switch is closed? 2. Relevant equations IR=V 3. The attempt at a solution I found that I1=5.2A and that I2=9.1A. The answers follow suit. Now I thought that calculating the combined resistance with 60/(I1+I2) would be correct, however the answer is 4Ω. Can anybody help me out in this? Thanks.