Answer: -30%
Step-by-step explanation:
The Nominal gain is:
= 100,000 - 20,000
= 80,000 foci
Tax on nominal gain:
= 20% * 80,000
= 16,000 foci
After tax nominal value of land:
= 100,000 - 16,000
= 84,000 foci
The real value given the price index is:
= 84,000 / 600 * 100
= 14,000 foci
After tax real rate of cap. gain:
= (14,000 - 20,000) / 20,000
= -30%