What are the final temperatures of the water and the aluminum in Celsius?

A piece of aluminum (specific heat 0.910kJ/kg .C) of mass 171.9g at 78.1 C is dropped into a Styrofoam cup filled with 143.8ml water at 20 C. What are the final temperatures of the water and the aluminum (in 'c)? Hint 1: because the cup is well-insulated, you can assume that all the heat leaving the aluminum as it cools goes to heating the water. Hint 2: How are the final temperature of the aluminum related to the final temperature of the water? (Use 4.19KJ/kgoC for the specific heat of water.)