Respond to the following independent situations:

Required:

a$.$ Chris and Casey, married filing jointly, earn $$250,000$ in salaries and do not have any net investment income.

b$.$ Chris and Casey, married filing jointly, earn $$180,000$ in salaries and $$40,000$ in capital gains, $$40,000$ in dividends, and $$20,000$ in savings interest for a total modified AGI of $$280,000.$

c$.$ Chris and Casey, married filing jointly, earn $$300,000$ in salaries and $$40,000$ in capital gains for a total modified AGI of $$340,000.$

How much in surtax will Chris and Casey be assessed on their Form $1040$ for $2022?$

Amount of surtax

a$.$

b$.$

c$.$