Inherited Property Sold

Question

Due to the sale of an inherited dwelling in May this year I am now facing an income tax return with CGT involved and I want to know how the capital gain can be calculated. Specifically, which year will be the cost base, will partial exemption apply and will the 50% discount apply?
My partner purchased a unit in Sydney on 02-09-1988 for $180,000.
This unit was her main residence from date of purchase, 02-09-1988 until July 1998.
The unit was rented continuously from 11-07-1998 until it was sold on 03-04-2014 and she owned no other property.
My partner passed away on 12 Jan 2010 and I inherited the unit.
The unit was sold at auction on 03-04-2014 for $805,000
Settlement on 15-05-2014
Costs to acquire the unit about $2,500?
Costs of sale $22,127
Valuations:
1998 $320,000
Jan 2010 $675,000

Answer

It is clear that you are saying that my cost base would be the 1998 valuation of $320,000 but I am not sure what you are saying about partial exemption eligibilty.