Thermodynamics question.. entropy?

Question

A fluid has an entropy of 4000 kJ/kg.K and a temperature of 300K in its initial state. It is reduced by heat transfer to 1000 kJ/kg.K at the same temperature. If the same quantity of heat transfer at a temperature of 450K is transferred ending up at an entropy of 1000 kJ/kg.K, what is the initial entropy?

Answer 1

DeltaS(entropy)=DeltaQ/T when T is constant

1000-4000=Q/350

-3000*350=Q=1050000 kJ/kg

1000-s1=1050000/400

-s1=-2625-1000

s1=3625 kJ/kg.K