A ceramic coffee cup, with m = 137 g and c = 1090 J/(kgK), is initially at room temperature (24.0°C). If 265 g of 80.3°C coffee and 12.2 g of 5.00°C cream are added to the cup, what is the equilibrium temperature of the system? Assume that no heat is exchanged with the surroundings, and that the specific heat of coffee and cream are the same as the specific heat of water. I tried to use the equation c=Q/(mdeltaT) but I'm not sure what to plug in for Q because I can't calculate its value. Am I completely off track about the equation?