During construction of the Quebec Bridge in 1907, the bridge’s designer, Theodore Cooper, received word that the suspended span being built out from the bridge’s cantilever was deflecting downward by a fraction of an inch. Before he could telegraph to freeze the project, the whole cantilever arm broke off and plunged, along with seven dozens workers, into the St. Lawrence River. It was the worst bridge construction disaster in history. As a direct result of the inquiry that followed, the engineering “rules of thumb” by which thousands of bridges had been built went down with the Quebec Bridge. Twentieth-century bridge engineers would thereafter depend on far more rigorous applications of mathematical analysis.
Which one of the following statements can be properly inferred from the passage?
(A) Bridges built before about 1907 were built without thorough mathematical analysis and, therefore, were unsafe for the public to use.
(B) Cooper’s absence from the Quebec Bridge construction site resulted in the breaking off of the cantilever.
(C) Nineteenth-century bridge engineers relied on their rules of thumb because analytical methods were inadequate to solve their design problems.
(D) Only a more rigorous application of mathematical analysis to the design of the Quebec Bridge could have prevented its collapse.
(E) Prior to 1907 the mathematical analysis incorporated in engineering rules of thumb was insufficient to completely assure the safety of bridges under construction.
Theodore Cooper CR
This topic has expert replies
IMO E. Inference questions are tricky ones, so m mot sure, but i select E from A and E coz only these 2 options make sense as per the context of the passage given above. You know, i selected A first, but then on re-reading twice, i selected E.
please post the OA. Also, please tell me is this question a LSAT question??
![Smile :)](./images/smilies/smile.png)
please post the OA. Also, please tell me is this question a LSAT question??
![Smile :)](./images/smilies/smile.png)
-
- Legendary Member
- Posts: 1161
- Joined: Mon May 12, 2008 2:52 am
- Location: Sydney
- Thanked: 23 times
- Followed by:1 members
-
- Master | Next Rank: 500 Posts
- Posts: 377
- Joined: Wed Sep 03, 2008 9:30 am
- Thanked: 15 times
- Followed by:2 members
Between A and E
A can be irrelevant because nothing has been mentioned in the argument about the thorough mathematical analysis not being use prior to 1907
E is correct.....mathematical analysis was insufficient
A can be irrelevant because nothing has been mentioned in the argument about the thorough mathematical analysis not being use prior to 1907
E is correct.....mathematical analysis was insufficient
GMAT/MBA Expert
- lunarpower
- GMAT Instructor
- Posts: 3380
- Joined: Mon Mar 03, 2008 1:20 am
- Thanked: 2256 times
- Followed by:1535 members
- GMAT Score:800
first, this problem isn't written in a gmat-like style at all. real gmat passages never waste your time with flowery narrative.
be aware.
--
remember that "inferences" don't mean what they do in normal conversation. instead, an "inference", for gmat purposes, is something that ABSOLUTELY MUST be true based on the premises of the argument.
note that (e) ABSOLUTELY MUST be true, because the rules-of-thumb were being used ... but ... there were still unsafe bridges. that's enough to PROVE that the existing rules-of-thumb were insufficient to assure the safety of the bridges.
none of the other choices ABSOLUTELY MUST be true. if you don't understand why not, feel free to post back.
be aware.
--
remember that "inferences" don't mean what they do in normal conversation. instead, an "inference", for gmat purposes, is something that ABSOLUTELY MUST be true based on the premises of the argument.
note that (e) ABSOLUTELY MUST be true, because the rules-of-thumb were being used ... but ... there were still unsafe bridges. that's enough to PROVE that the existing rules-of-thumb were insufficient to assure the safety of the bridges.
none of the other choices ABSOLUTELY MUST be true. if you don't understand why not, feel free to post back.
Ron has been teaching various standardized tests for 20 years.
--
Pueden hacerle preguntas a Ron en castellano
Potete chiedere domande a Ron in italiano
On peut poser des questions à Ron en français
Voit esittää kysymyksiä Ron:lle myös suomeksi
--
Quand on se sent bien dans un vêtement, tout peut arriver. Un bon vêtement, c'est un passeport pour le bonheur.
Yves Saint-Laurent
--
Learn more about ron
--
Pueden hacerle preguntas a Ron en castellano
Potete chiedere domande a Ron in italiano
On peut poser des questions à Ron en français
Voit esittää kysymyksiä Ron:lle myös suomeksi
--
Quand on se sent bien dans un vêtement, tout peut arriver. Un bon vêtement, c'est un passeport pour le bonheur.
Yves Saint-Laurent
--
Learn more about ron
GMAT/MBA Expert
- lunarpower
- GMAT Instructor
- Posts: 3380
- Joined: Mon Mar 03, 2008 1:20 am
- Thanked: 2256 times
- Followed by:1535 members
- GMAT Score:800
i received a private message about this thread.
yes, "inferences" are EXACTLY the same as "conclusions that can be properly drawn".
indeed.
yes, "inferences" are EXACTLY the same as "conclusions that can be properly drawn".
indeed.
Ron has been teaching various standardized tests for 20 years.
--
Pueden hacerle preguntas a Ron en castellano
Potete chiedere domande a Ron in italiano
On peut poser des questions à Ron en français
Voit esittää kysymyksiä Ron:lle myös suomeksi
--
Quand on se sent bien dans un vêtement, tout peut arriver. Un bon vêtement, c'est un passeport pour le bonheur.
Yves Saint-Laurent
--
Learn more about ron
--
Pueden hacerle preguntas a Ron en castellano
Potete chiedere domande a Ron in italiano
On peut poser des questions à Ron en français
Voit esittää kysymyksiä Ron:lle myös suomeksi
--
Quand on se sent bien dans un vêtement, tout peut arriver. Un bon vêtement, c'est un passeport pour le bonheur.
Yves Saint-Laurent
--
Learn more about ron
-
- Legendary Member
- Posts: 882
- Joined: Fri Feb 20, 2009 2:57 pm
- Thanked: 15 times
- Followed by:1 members
- GMAT Score:690
[quote]none of the other choices ABSOLUTELY MUST be true. if you don't understand why not, feel free to post back.[/quote]
can you explain why not C?
can you explain why not C?
GMAT/MBA Expert
- lunarpower
- GMAT Instructor
- Posts: 3380
- Joined: Mon Mar 03, 2008 1:20 am
- Thanked: 2256 times
- Followed by:1535 members
- GMAT Score:800
we know that previous engineers relied on "rules of thumb", but we are not given any indication as to why they relied on those rules. this answer choice pretty much just makes up a reason (analytical methods were inadequate) out of nowhere.crackgmat007 wrote:can you explain why not C?none of the other choices ABSOLUTELY MUST be true. if you don't understand why not, feel free to post back.
there could perfectly well be other reasons, such as "the analytical methods worked but were too time-consuming, laborious, and/or difficult to be used on a routine basis".
but you shouldn't have to think up alternative reasons.
as soon as you see "because..." in this post, you should realize that they're about to supply a reason - which has nothing to do with the passage (because the passage doesn't supply any reason).
Ron has been teaching various standardized tests for 20 years.
--
Pueden hacerle preguntas a Ron en castellano
Potete chiedere domande a Ron in italiano
On peut poser des questions à Ron en français
Voit esittää kysymyksiä Ron:lle myös suomeksi
--
Quand on se sent bien dans un vêtement, tout peut arriver. Un bon vêtement, c'est un passeport pour le bonheur.
Yves Saint-Laurent
--
Learn more about ron
--
Pueden hacerle preguntas a Ron en castellano
Potete chiedere domande a Ron in italiano
On peut poser des questions à Ron en français
Voit esittää kysymyksiä Ron:lle myös suomeksi
--
Quand on se sent bien dans un vêtement, tout peut arriver. Un bon vêtement, c'est un passeport pour le bonheur.
Yves Saint-Laurent
--
Learn more about ron
-
- Legendary Member
- Posts: 882
- Joined: Fri Feb 20, 2009 2:57 pm
- Thanked: 15 times
- Followed by:1 members
- GMAT Score:690