Question

In a physics lab experiment, a student immersed 205 one-cent coins (each having a mass of 3.00 g *.003kg) in boiling water. After they reached thermal equilibrium, she quickly fished them out and dropped them into 0.244 kg of water at 20.0 C in an insulated container of negligible mass.

What was the final temperature of the coins? [One-cent coins are made of a metal alloy - mostly zinc - with a specific heat capacity of 390 J/(kg*K).]


I know that:
Mass,coins=.615 kg
Mass,water=.244 kg
c=390 J/(kg*K)
Ti,water=20 C

I'm just not quite sure what equation to put them in...