What is the Final Temperature of the White Coffee?

[bidhati]

Homework Statement

A person has 300 g of black coffee at temperature 350 K in a vacuum
flask. 100 g of milk at 280 K are added to the coffee (the flask is immediately closed, so the loss of heat to the air is negligible). Assuming that the specific heat capacities of the coffee and milk are equal, calculate the temperature of the white coffee (black coffee + milk) after the milk has been added.

Homework Equations

C = Q/ delta T
T = m1*C1*T1 + m2*C2*T2 / M*C2 + m1*C1

The Attempt at a Solution

This is where I am going mad I am not given specific heat capacities thus I have no idea as too how to go about solving this problem.

 

[nicktacik]

If C1=C2, then you can factor all those terms out...

 

[bidhati]

thank you