A 20g piece of iron (specific heat capacity $=0.5\mathrm{J}/g^{\circ }\mathrm{C}$ ) at ${200}^{\circ }\mathrm{C}$ is immersed in 100g water of ${27}^{\circ }\mathrm{C}$ . What will be the temperature $\left({ }^{\circ }\mathrm{C}\right.)$ of this system of thermal equilibrium