1. The problem statement, all variables and given/known data Find the current marked I3 in the circuit. 2. Relevant equations 3. The attempt at a solution The voltage over R2 and R1 is the same. The current I0 (12mA) is the sum of I2 and I1. I1*R1 = I2*R2: 4*I1 = 1.25*I2 I1 + I2 = 12 <=> I2 = 12 - I1 4*I1 = 1.25*(12 - I1) = 15 - 1.25I1 5.25*I1 = 15 I1 = 2.86 I think I've messed up already here. Can anyone spot what I'm doing wrong??