The amount of heat energy lost by the metal is
E = 200 J/kg*C x 1.5kg x (100–20) = 24000 J
That is transferred to the liquid, raising it's temperature
24000 J = 1,000 kg/J*C x 3kg x ∆T
∆T = 8
Since the liquid started at 0ºC, the final temp is 8ºC
