Water Sports Ltd$.$ pays $$360$ less $25\%$ for a backyard above$-$ground pool kit. Overhead expenses are $16\_23\%$ of the regular selling price, and the operating profit is $15\%$ of the selling price. a$.$ What is the maximum rate of markdown the store can offer and still break even?

b$.$ What is the profit or loss per unit if Water Sports clears out its remaining stock at $20\%$ off

in its Hot August Bargains Sale? $($answer in textbook a$\mathrm{.}15\%$ b$.$$$19\mathrm{.}76$ loss$)$