1. The problem statement, all variables and given/known data In the circuit shown in the figure (attached with the solution). Determine: 1. the reading of the ammeter when the key (K) is open. 2. The reading of the ammeter when the key (K) is closed. 2. Relevant equations 3. The attempt at a solution What confuses me in the circuit above is that when the key is open, I will have only one loop to work on, and that will make only one equation (equation no.2) and then I will have two unknown values, and I will not be able to find i₂ (the current passing through the ammeter), so what should I do here?