Nitrobenzene, C₆H₅NO₂, and benzene, C₆H₆, are completely miscible in each other. Other properties of the two liquids are nitrobenzene: fp = 5.7 °C, K_f = 8.1 °C kg mol^-1; benzene: fp = 5.5 °C, K_f = 5.12 °C kg mol^-1. It is possible to prepare two different solutions with these two liquids having a freezing point of 0.0 °C. What are the compositions of these two solutions, expressed as mass percent nitrobenzene?