# All oceangoing ships carry seawater ballast tanks whose weight improves stability. To maintain the ship's proper stab...

Cirrus on November 22, 2019

Need help, thanks.

Replies

Skylar on November 22, 2019

@cjahangiri, Happy to help!

This is a Strengthen with a Necessary Premise question, so we know that the negation of the correct answer will cause the argument in the passage to fall apart. We also know that the conclusion of the argument given in the passage is that "one viable way of addressing this problem would be to empty and then immediately refill the tanks in midocean."

The negation of (E) - "There are NO oceangoing ships whose stability could be adequately maintained while emptying and refilling their ballast tanks in midocean"- does just this. If no ship would be able to refill its tanks in midocean without losing its stability and tipping over, doing so would not be a viable solution. This makes the passage's argument fall apart, so (E) is correct.

Does that help? Let us know if you have any other questions!

on November 30, 2019

What about C? What if creatures can wreak havoc in environments even if they are unable to survive in that environment? Wouldn't that make the solution of emptying the tanks mid-ocean not viable?

Skylar on December 1, 2019

@tomgbean, happy to help!

(C) can be a really tricky answer for students. Ultimately though, the negation of (C) does not make the argument fall apart.

Firstly, (C) is only talking about what creatures "have been able" to do in the past, not necessarily what they can do or what they would do if this new solution were to be implemented.

Secondly, (C) basically says that sea creatures do not often wreak havoc in a new habitat UNLESS they have been able to survive in that habitat after oceangoing ships deposit them there. If the creatures are able to wreak havoc in new environments both when deposited/surviving there by oceangoing ships and when not, the argument does not change. The negation of (C) deals largely with non-deposited situations, which is irrelevant to our purposes and goes beyond what is NECESSARY for the argument.

Does that make sense? Please let us know if you have any additional questions!

on December 2, 2019

Yes it does. Thanks!

on August 26, 2020

Why is A wrong?