Gudenas Company makes a credit card sale to a customer for $$500.$ The credit card sale has a grace period of $30$ days and then an interest charge of $18\%$ per year or $1\mathrm{.}5\%$ per month is added to the balance. If the unpaid balance on the above sale is $$300$ at the er of the grace period, the interest charge is

$$4\mathrm{.}50$

$$7\mathrm{.}50$

$$3\mathrm{.}00$

$$5\mathrm{.}00$