We have again a sphere that is cooling down and a sphere that is evaporating. So, we are going to take a look at the analogy between heat and mass transfer, but now analogy does not mean that the complete analysis and outcome of the one is the same as for the other. For the cooling down case, there is only conduction, so Nusselt is 2. And for the evaporating case, there is only diffusion on the outside, so Sherwood is 2. So, there is no convective flow in both cases. Set up an energy balance for the first case, and a mass balance for the second case and solve both. After that, you can compare them and look to the analogy.