An answering system including a first mobile phone, the first mobile phone includes a communication unit for communicating with a second mobile phone, a position sensor, a microphone, and a processor. The position sensor detects whether the first mobile phone is flat or tilted (balanced state or unbalanced state). The microphone detects vocal commands given to the first mobile phone. The processor acknowledges any incoming call when the first mobile phone is positioned in an unbalanced state and a conversation is detected in a preset time, and hangs up a call received previously when no command or conversation is detected in the preset time and the first mobile phone is positioned in a balanced state.