Hey everyone, im having some trouble with an assignment question which is due in a few hours. Could anyone please help me try to understand the question as i am quite stumped. Any help would be appreciated

A 0.350 kg sample is placed in a cooling apparatus that removes energy as heat at a constant rate. The figure below gives the temperature T of the sample versus time t; the horizontal scale is set by ts = 80.0 min. The sample freezes during the energy removal. The specific heat of the sample in its initial liquid phase is 2400 J/kg·K. The value of K between the substance's liquid only and liquid + solid state is 30K and the value of K between the substance's liquid + solid state and solid only state is 20K. Any help would be much appreciated.

(a) What is the sample's heat of fusion (in J/kg.K)?
(b) What is its specific heat in the frozen phase (in J/kg.K)?