Direct vs. Indirect Variation

The volume of the water in a swimming pool as it is filled at a rate of 200 gallons per minute.
I said this is direct variation V = 200t

The volume of the water in a swimming pool as the water drains at a rate of 200 gallons per minute.
I believe that this would also be direct variation?? Such as V = -200t?

But the answer packet says it is neither direct nor inverse variation.

1 answer

no
V = F - 200 t

Where F is the full volume