paid $$1,005\mathrm{.}29$ per bond and the flotation cost was $$17\mathrm{.}51$ per bond. Pepsi's corporate tax rate is $21\%.$

a$.$ Ignoring flotation costs, what is Pepsi's before$-$tax and after$-$tax costs of debt?

b$.$ Considering flotation costs, what is Pepsi's before$-$tax and after$-$tax costs of debt?