When 100 g of boiling water at 100∘C is added into a calorimeter containing 300 g of cold water at 10∘C, temperature of the mixture becomes 20∘C. Then a metallic block of mass 1 kg at 10∘C is dipped into the mixture in the calorimeter. After reaching thermal equilibrium, the final temperature becomes 19∘C. What is the specific heat of the metal in C.G.S. units?