You drop an ice cube into an insulated flask full of water and wait for the ice cube to completely melt. The ice cube initially
has a mass of 60.0 g and a temperature of 0°C. The water (before the ice cube is added) has a mass of 760 g and an initial temperature of 20.0°C. What is the final temperature (in °C) of the mixture? (Assume no energy is lost to the walls of the flask, or to the environment.)