We don't have any evidence that tells us whether certain animals take less time to care for than others. So, we are going to rely on some reasonable assumptions.

No, you can't just make this stuff up. Your assumptions have to be "reasonable"!

For example:

Think about what has to be done to care for a dog. You have to feed a dog, and brush a dog, and it's also important to take a dog for walks after every meal.

Compare that with the chores involved in caring for a fish. You have to feed a fish, and you have to clean out its tank now and then. But you don't have to brush a fish, or take your fish for walks after every meal. (Ever seen your next door neighbor taking her guppy for an early evening stroll?)

It's reasonable to say that fish take less time to care for than dogs. So, we can reasonably assume that some animals take less time to care for than others.

In other words, we will assume that Part 1 of our second hypothesis is true.

Woo Hoo!