If the volume of water in the tank at the time is Vt then wouldn't it just be 0?
We have the equation :
Vt = V0kt where V0 = 3000 = the original volume and t is the number of hours
So....when t = 2 we have
2881.2 = 3000k2 divide both sides by 3000
2881.2 / 3000 = k2 take the square root of both sides
0.98 = k
This means that every hour after V0, the tanks loses 1 - .98 = .02 = 2% of its water from the previous hour
So
k = 0.98 and x = 2%