Q18 - Traffic engineers have increased

[jennifer]

Why is answer choice E incorrect? B and E both looked good, however I thought answer choice B was too strong, that perhaps there were other factors that could have contributed to the problem

[ManhattanPrepLSAT1]

This is a question that asks us to find an answer choice that must be true given the statements in the stimulus. A common form of a tempting but incorrect answer on such a question is an answer choice that represents a statement that comes from a kernel of truth but goes too far with the information (ie; the claim is stronger than can be supported by the given information). In this case, while answer choice (B) is strong, it can be supported by the given information.

There are 2 conditional statements in the stimulus, and the correct answer choice (B) simply applies the transitive property and combines them.

~ICM ---> ~IT
~IT ---> ~FPR

Notation Key: ICM - invest in computer modeling, IT - increased traffic, FPR - financial predicament resolved

From these 2 claims we can infer

~ICM ---> ~FPR

In English: If they had not invested in computer modeling, they would not have resolved the city's financial predicament - best expressed in answer choice (B).

Let's look at the incorrect answer choices:

(A) plays the "what if game." We don't know what would have happened had the city chosen a competing computer modeling software package.
(C) may be tempting if you fail to notice that the statements only discuss "rush-hour traffic".
(D) is unsupported. We aren't given any information to confirm that either the mayor was involved in the decision nor that investing in computer modeling technology was the highest budgetary priority last year.
(E) is unsupported. We aren't given any information to confirm that the mayor was involved in the decision nor were we given information to suggest even if the mayor was a supporter of the investment in computer modeling technology why the mayor would have supported such a choice.

Hope that helps!

[emilymurray265]

Understanding how to diagram these statements is really confusing me. I read somewhere about how to diagram statements with 'would'.

Reading the stimulus I could not figure out how to diagram. How do you know that ~ICM is the sufficient condition for the first sentence?

Essentially, I am having way too much trouble with this one question and it's bugging me.

I need help please!

[branjof94]

Can it also be translated as Tech -> Increased Traffic ( - Increased traffic --> -tech)
Increased Traffic --> $Solved ( -$solved-> - Increased traffic )


therefore -$solved -> -tech Answer B

or did I get the right answer for the wrong reason?

[ohthatpatrick]

Yes. Right answer, wrong reason.

Basically, you symbolized all three of them backwards, so your chain still worked.

Since all three conditionals (the two from the stim and the one from choice A) used the same wording of "X would have have occurred without Y", it didn't mess you up that in each case you were writing them backwards.

So be careful and make sure you understand why the wording of "X wouldn't have occurred without Y" is symbolized as X --> Y

Otherwise, you'd risk missing (A) if it had been (equivalently) stated as
(A) If the financial predicament was resolved, then the city chose a competing package.

Here's a sports metaphor, if that happens to work for you. In the NBA, the Cleveland Cavs are generally a terrible team that never even makes it into the playoffs. This year, though, the best player in the world (Lebron James) joined their team and they made it all the way to the NBA Finals.

I can say, "The Cavs would not have gotten to the NBA Finals had Lebron not joined their team."

Does that feel more like
WITHOUT Lebron, there's no way the Cavs would make the NBA Finals
or
WITH Lebron, it's a guarantee that the Cavs make the NBA Finals ?
(it can't be both, you have to pick)

It's the 1st one. Having Lebron doesn't guarantee they make it to the Finals, but not-having Lebron guarantees.

When you read a conditional sentence and hear something that sounds required, the required thing goes on the right side of the arrow.

They needed Lebron to make the Finals:
Making the Finals ----(required)----> Lebron

Without Lebron, they wouldn't make the Finals.

They needed the new computer technology to increase the traffic flow on the bridge:
Increasing traffic flow ----(required)----> new tech

Without new tech, they wouldn't have increased traffic flow.

Hope this helps.