The net price of an item after trade discounts of $34\mathrm{.}00\%,13\mathrm{.}00\%,$ and $3\mathrm{.}50\%$ is

$$3,120\mathrm{.}00.$

a$.$ Calculate the regular selling price of the goods.

Round to the nearest cent

b$.$ Calculate the equivalent discount rate of the series of discount rates.

$\%$

Round to two decimal places