capital gain tax on inherited property

two sons inherited a house from parent and sold in the current financial year then how the capital gain tax would be computed. the land was purchased by the parent in 1985 and the house constructed in 1995 and construction of first floor in 1997. the property transferred to two sons in FY 2014-15 and sold by them in FY 17-18. also please note that the property is beyond 8km limit of any municipal area. kindly suggest.