A piece of metal is heated to 428 degree celsius before it is left to cool. The temperature of the metal falls at a rate of 23 degree celsius per minute for the first 3 minutes, at a rate of 15 degree celsius per minute for the next 15 minutes and then at a rate of 8 degree celsius per minute until it reaches room temperature of 25 degree celsius. Find the temperature of the metal after 9 minutes.
