$[$The following information applies to the questions displayed below.$]$

In $2010$ Casey made a taxable gift of $$5\mathrm{.}5$ million to both Stephanie and Linda $($a total of $$11\mathrm{.}0$ million in taxable gifts$).$

Calculate the amount of gift tax due this year and Casey's unused applicable credit under the following alternatives. $($Refer

to Exhibit $25-1$ and Exhibit $25-2.)$

Note: Enter your answers in dollars, not millions of dollars. Leave no answer blank. Enter zero if applicable.

a$.$ This year Casey made a taxable gift of $$1$ million to Stephanie. Casey is not married, and the $2010$ gift was the only other taxable gift

he has ever made.