Answer: 25%
Explanation:
Municipal bonds are tax-free which means that the tax bracket that would make you indifferent between the 2 bonds would be the one that brings the after-tax yield on the taxable bond to the same yield as the Municipal bond.
Assume this tax rate to be x.
8% * ( 1 - x) = 6%
8% - 0.08x = 6%
0.08x = 8% - 6%
x = (8% - 6%) / 0.08
x = 25%
