Critical Reasoning

To avoid economic collapse, Russia must
increase its GNP by 20%. However, due to the
structure of its economy, if the 20% threshold is
reached, then a 40% increase in GNP is
achievable.
Assuming that the above statements are true,
which one of the following must also be true?
(A) If ethnic strife continues in Russia, then a
20% increase in GNP will be unattainable.
(B) If a 40% increase in Russia’s GNP is
impossible, its economy will collapse.
(C) If Russia’s GNP increases by 40%, its
economy will not collapse.
(D) If the 20% threshold is reached, then a
40% increase in GNP is achievable and a
60% increase is probable.
(E) If Russia’s economy collapses, then it will
not have increased its GNP by 40%.

A - Achieve 40 %
B- Avoid collapse

A -> B

negating

Not B -> Not A

Answer should be E

C looks to be the correct one rather than E.


But I think the OA is B. It uses diagramming and logic. I feel its too LSAT specific.

now this is what i call a good question.
is the answer B ,if yes will explain further.

C

A. out of scope

B. 20%-> No economic collapse
20%-> 40 % is achievable but cant take it for sure.
C. if 40% increase then 40% can not be reached without 20% increase.
Correct.

D, Cant comment about 60%. Not mentioned in the passage.
E.Cant say that , the requirement is just 20%, not 40%

B for me

1) GNP increase <20% - Economy collapses

2) if 20% increase reached, then 40% reachable
=>40% increase impossible=> 20% increase not reached (<20%)=>economy collapses

I always thought that
if A => B then
not B => not A

And based on this analysis B, C and E all seem good so i dont know how to proceed further

(A) If ethnic strife continues in Russia, then a
20% increase in GNP will be unattainable.

OUT OF SCOPE

(B) If a 40% increase in Russia’s GNP is
impossible, its economy will collapse.

A = 40% increase in Russia’s GNP is
impossible

B = economy will collapse.

not B = Russian economy will not collapse
not A = 40% increase in GNP is possible
So if the economy will not collapse then we know for sure that Russia would have definitely got past the 20% threshold. But the 40% increase could be achievable in other words possible so B is a good candidate. Dont rule it out yet

(C) If Russia’s GNP increases by 40%, its
economy will not collapse.

A = GNP increases by 40%
B = economy will not collapse


So If the economy collpases then GNP will not increase by 40%. Another good candidate since we know for certain that the economy collapsed Russia never made the 20% threshold hence its GNP never increased by 40%




(D) If the 20% threshold is reached, then a
40% increase in GNP is achievable and a
60% increase is probable.


OUT OF SCOPE

(E) If Russia’s economy collapses, then it will
not have increased its GNP by 40%.

A = economy collapses
B = GNP increased by 40%.


If Russia increased its GNP by 40% then its economy would not have collapsed. Another good candidate

So in the end we have three options which are close
B, C and E
Which one is the best?

This is really an excellent question and I look forward to viewing the OA.

That said, my contenders are
D and E but I vote for D.

I eliminated E because it almost passes the negation test of If A--> B = Not A--> Not B

To underscore my point let's examine the conclusion in the stimulus "To avoid economic collapse, Russia must increase its GNP by 20%. " which we can translate to IF A (Russia must increase its GNP by 20%) --> B (To avoid economic collapse).

Now let's translate the statement in E into Not A --> Not B and you'll notice that the exam tester has subtly switched around the conclusion into the condition and the condition into the conclusion giving us Not B (If Russia’s economy collapses) --> Not A (then it will not have increased its GNP by 40%.).

I definitely vote for Option D.

More questions like these please!!

OA is E, Its from Kaplan 800

Naruto wrote:OA is E, Its from Kaplan 800

Thanks for confirming.

I thought it was B. The below link confirms the same:

https://www.novapress.net/diagnostic/lsa ... t_sol.html

Here are my reasons. Economy can collapse because of many factors. One of them is failure in GNP increment by 20%. But, if GNP increases by 20%, there is 100% probability that GNP CAN increase by 40%, i.e. 0% probability that GNP increment of 40% is impossible.
Hence, if the chances of GNP going 40% up > 0%, the GNP DID NOT increase by the threshold of 20%, one of the factors to keep economy up and running. Failure of any factor will cause collapse. Hence, economy collapses. Hence B.

C and E both make the 20% threshold value a sufficient condition for economy to sustain. While I believe it is a necessary factor, I don't agree it is a sufficient one.

I am pretty sure that the right Answer is B.