Amelia deposits $$500$ into a savings account that earns $4\%$ simple interest, for $2$ years. On the same day, her brother Caleb deposits $$200$ into a savings that earns $5\%$ simple interest, for $3$ years.

a$.$ Who will earn more interest? $($Show a full solution$)$

b$.$ Who has the greater rate of return? $($Support your decision with evidence$)$

I