A wine bottle contains 30 litres of
pure wine. 10 litres of it is replaced with 20 litres of water. Then 10
litres of the resulting solution is again replaced with 20 litres of
water. What is the volume of pure wine (in litres) in the container
after eight such operations?

1) 273/40
2) 5
3) 273/35
4) 6
5) Cannot be Possible