AC Power Accounting

Let $P_R$ be the combined power (in watts) consumed by all of the resistors in the circuit. Let $P_1$ be the power (in watts) supplied by ideal voltage source $V_1$ to the rest of the circuit.

What is $\large{\frac{P_1}{P_R}}$ ?

Details:
1) Voltage magnitudes $(V_1, V_2, V_3, V_4) = (15, 10, 12, 15)$ . All voltage source phase angles equal

Hint: If the voltage of the source is $V_1$ and the current flowing out of the source is $I_1$ , the active power flowing out of the source is $Re[V_1 \, I_1^*]$ , where the " $*$ " symbol denotes the complex conjugate of the current. If we calculate the powers flowing out of all sources and add them up, how does the sum compare to the total power consumed by the resistors?