A married couple from California is in the $31\%$ Federal tax bracket and the $8\%$ California tax bracket. They are

considering a $51\frac{1}{4}\%$ Hawaii municipal bond $($Federal tax$-$free$),$ a $5\%$ California bond $($double tax$-$free$)$ or a $\frac{73}{4}$

corporate bond $($fully$-$taxable$).$ Which bond offers the highest after$-$tax interest rate?

A California investor is in the $35\%$ Federal tax bracket and the $9\%$ California tax bracket. He has the choice of a

$5\%$ Oregon municipal bond $($Federal tax$-$free$),$ a $4\frac{1}{4}\%$ California bond $($double tax$-$free$)$ or a $7\frac{1}{2}\%$ corporate bond

$($fully$-$taxable$).$ Which bond offers the highest after$-$tax interest rate?