Question

Q.an aluminium can of mass 200gm contains 500gms of water at 50c.an ice cube of mass 50gms,initially at a temperature of -20c is thrown into the can of water.
i.what is the final temperature onces the ice metls and comes into equilibrium?
ii.now a 200gm piece of Iron whose temperature is 200c is thrown into the can.what is the new equilibrium temperature.
specific heats:cal/gm-deg
water-1.0
ice-0.5
Iron-0.1
Al-0.2
finally what mass of ice would have to be thrown in initially so that it just barely melts?