A cube of niobium measuring 5×5×3 cm and another cube of tungsten measuring 3×3×5 cm are melted together in a crucible to form an alloy. From the phase diagram provided:
a. Determine the liquidus temperature, the solidus temperature and the freezing range of the alloy.
b. Determine the phase(s) present, their composition(s) and their amount(s) at 2800 °C.