3. Imagine you fill your bathtub up at a rate of 2 gallons per minute. This means that every minute you should have 2 more gallons of water than in the minute prior. Suppose you drain the tub at a rate of 0.5 gallons per minute. This means that every minute you will see 0.5 gallons of water leave through the drain. So, what is the net rate of water change per minute? Since each minute 2 gallons are gained and 0.5 gallons are lost, we expect a net gain of 1.5 gallons per minute. Let's think about a population in a similar way: inflow outflow net rate rate rate Regardless of the particular application (i.e. populations, water, temperature, etc.), this can be better seen by using the bathtub analogy below: populucion A d