The Continental Bank advertises capital savings at $7\mathrm{.}9\%$ compounded annually while TD Canada Trust offers premium savings at $7\mathrm{.}65\%$ compounded monthly. Suppose you have $$$$2000$ to invest for two years.

$($a$)$ Which deposit will earn more$$ interest?

$($b$)$ What is the difference in the amount of$$ interest?