The reading on ammeter 3 will be the same as that on ammeter 1, which is 0.1 A. Explanation: In a series circuit, current is the same through all components since the current has only one path to take. If ammeter 1 shows 0.1 A, it means the current flowing through the circuit at that point is 0.1 A, and therefore the current measured on ammeter 3, placed along the same series path, will also be 0.1 A. This holds true assuming ideal ammeters with negligible resistance and no parallel branches diverting current between these points.