Katherine, a resident of North Carolina, had the following bond portfolio in $2023.$ Katherine is in the $20\%$ Federal Income Tax Bracket and the $6\%$ State Income Tax Bracket. Federal Capital Gains tax at $15\%$ and State Capital Gains at $5\%.$ SHOW INTEREST RATES TO $2$ DIGITS $($X$.$XX$\%)$

APPL Bond, face value $$75,000,$ coupon semiannual, $6\mathrm{.}25\%,$ maturity $2033.$

NC State Bond, Face Value $$100,000$ coupon annual, $4\mathrm{.}75\%$ maturity $2032.$

US Government Treasury Bond $$150,000$ coupon semiannual, $5\mathrm{.}25\%$ maturity $2035$

a$.$ How much tax does Katherine pay on this portfolio in $2023?3$ Points

b$.$ What is the after$-$tax interest rate for each bond? $3$ Points And

c$.$ What is the after$-$tax interest rate for the total portfolio? $3$ Points