The resistors in the circuit diagram are all identical. Voltmeter $V_2$ shows a reading of $1.5\,\text{V}$. Ammeter $A_2$ has a reading of $0.50\,\text{A}$. Ammeter $A_3$ has a reading of $0.25\,\text{A}$. What are the readings shown by ammeter $A_1$ and voltmeter $V_1$?