#26 - All known deposits of the mineral tanzanite are in

[Adam Tyson]

Thanks for asking, z.em. The problem with answer C is that it goes a little backwards from what we wanted. C tells us that they only animals in the lagoon are frogs and that owls only eat frogs, and concludes that owls must only eat from the lagoon. But couldn't there be frogs all over the island, not just in the lagoon? C would be like the original argument saying that the only stones found in Tanzania are Tanzanite, rather than saying that Tanzanite is only found in Tanzania. In the former situation, there could be Tanzanite found elsewhere, just like in C there could be frogs outside the lagoon. Since our stimulus said the latter, though, C is not quite the same, and D is the better choice.

To double check it, do this - substitute "Tanzania" for "lagoon", substitute "deposits of Tanzanite" for "frogs on the island", and substitute "Ashley's collection" for "owl's diet". That should help you clarify it. D tracks the stimulus perfectly when you do that, but C does not.

I hope that helps!

[deck1134]

Hi PowerScore staff,

I hope you are having a happy fourth!

My question is somewhat general. I was reading through each answer choice and saying "Contender" or "Loser" based on a variety of factors rather than simply running thorough each test once. Is this okay? Do you, for instance, recommend going through each answer choice with each test to eliminate it? Or can I do it at the same time?

Thanks!

[Adam Tyson]

We recommend doing whatever is most efficient and useful for you, deck. If you have a good sense of the structure of the argument and can quickly see that an answer doesn't follow that structure for one reason or another, then call it a loser and move on with confidence. After you are done sorting, if you have more than one contender, that's when you should break out the tests like doubling the conclusion, doubling the premises, testing the abstract structure, etc. Similar to Assumption questions, were you first sort losers and contenders and then, if you have more than one contender, using the Assumption Negation Technique on them to find the best answer, you want to reserve the hard work of close examination and analysis for when you need it and only on those answer that are worthy of the effort. That's how you move through this test more efficiently, confidently, and accurately.