Critical Reasoning

For the last five years, the XYZ Courier Company has made regular delivery trips between Town A and Town B. The average time taken by the company's drivers to drive the round trip between the two towns, excluding the time taken for loading, unloading, and delivery, over that period has been 80 minutes. John, a driver for XYZ, needs to make a personal trip between the two towns; he figures that he should allow approximately 80 minutes for the round trip.

Which of the following, if true, does not call John's conclusion into question?



1. The route between Town A and Town B has been plagued by increasing congestion over the last five years, as the area's population has doubled during that time.



2 . Most of XYZ's courier vehicles are heavy trucks, for which speed limits are lower than for passenger vehicles.



3. Many of the packages carried by XYZ between Town A and Town B are large, high-security packages, for which the processes of loading, unloading, and delivery can take up to half the length of the trip itself.



4. John will make his personal trip at an hour when XYZ does not make delivery trips.



5. Before a freeway was built between Town A and Town B two years ago, the only routes between the two towns were state highways with multiple traffic lights and reduced-speed downtown zones.

C

IMO C but can someone please clarify why D is rejected?

John' conclusion: John, a driver for XYZ, needs to make a personal trip between the two towns; he figures that he should allow approximately 80 minutes for the round trip.

Now when the answers are true it should not trouble this conclusion, Thats what is asked.

3. Many of the packages carried by XYZ between Town A and Town B are large, high-security packages, for which the processes of loading, unloading, and delivery can take up to half the length of the trip itself.

The time that was calculated before was calculated without considering the time for loading, unloading, and delivery so even if its true its not gonna affect.

4. John will make his personal trip at an hour when XYZ does not make delivery trips.

Whether he makes his trip during work or free hours, its not gonna affect the time.


Correct me if I am wrong at any point[/quote]

can someone plz explain

Which part do you want the explanation?

why D rejected??????

D is rejected because even if he travels during his work hours, its not gonna affect his conclusion of allowing 80 minutes for trip from A to B. D wont affect the conclusion even if its true.

This is confusing, the question stem if u read and paraphrase, suggests that which of the following does not WEAKEN john conclusion...right..

Now, logically we actually assumed that since John trip is personal so he is not going to involve in loading / other activities

Thats why Op C is correct.

But i believe Op D is also correct:

John will make his personal trip at an hour when XYZ does not make delivery trips.

This statement strengthens the John's conclusion, it states that the time John take is even less than the Av. time (80 mins), unless the person who designed this question illogically assumes that in Op D personal trip can be just one way trip not a two-way. If that so, i believe that assumption will be illogical.

Hence IMO both Op C and Op D has to be the answers.

DO u have any Official Explanation for this question?????

Hi Atul,

If we paraphrase the question
"Which of the following, if true, does not call John's conclusion into question?
It would read as
Which one of the following would be most meaningful to the conclusion?

In this case answer choice C stands out making answer choice D out of context.

Hope I am not wrong.

Murali[/b]

A,B,E - all out

we need an option that does not call the conclusion into question i.e. an option that suggests that John will take 80 minutes

D - when XYZ,a company,does not make delivery trips. It may be that when XYZ makes delivery trips then there is congestion on the road and John will take more time.

C - clearly the answer. One of those questions where 2 options are close but one of them is clearly the answer

MURALIDHARGAJULA wrote:Hi Atul,

If we paraphrase the question
"Which of the following, if true, does not call John's conclusion into question?
It would read as
Which one of the following would be most meaningful to the conclusion?

In this case answer choice C stands out making answer choice D out of context.

Hope I am not wrong.

Murali[/b]

As per texts and books i guess, CALL INTO QUESTION types are WEAKEN TYPE QUESTIONS, so in that case i think my paraphrasing is correct, rest some expert may guide us both.

The argument exclused the time taken for loading, unloading and delivery.

In the light of this premise why to consider Op C at all?

Would B be a better answer...if courier vehicles are trucks then the maximum speed limit for trucks is less than speed limit for passenger vehicles(considering an assumption that John rides in a paasenger vehicle). It means passenger vehicles can travel faster than trucks thus time taken by them will be less. Thus 80 minutes are sufficient for the trip.

Expert help needed for this. I dont find C a good OP as an answer.

champmag wrote:The argument exclused the time taken for loading, unloading and delivery.

In the light of this premise why to consider Op C at all?

Would B be a better answer...if courier vehicles are trucks then the maximum speed limit for trucks is less than speed limit for passenger vehicles(considering an assumption that John rides in a paasenger vehicle). It means passenger vehicles can travel faster than trucks thus time taken by them will be less. Thus 80 minutes are sufficient for the trip.

Expert help needed for this. I dont find C a good OP as an answer.

I hear you but in that case u have to assume that John, in any case, will not go to town via Truck / courier vehicle, it may be possible that courier vehicle is John's own personal vehicle and he just using his vehicle to serve courier company to make some living like most of the cab drivers do in Bangalore.

Read the question stem carefully - the question asks which of the following does NOT call John's conclusion into question. This means that the right answer choice should not weaken his conclusion, and the four wrong answer choices should each weaken his conclusion.

What is John's conclusion? that he will take 80 minutes to make his trip.

This conclusion is based on the premise that it takes an average of 80 minutes to do the trip on a delivery route.

In other words, John's assumes that his personal trip will be the same as a regular delivery run. Any answer choice that proves this assumption wrong will weaken his conclusion that he needs 80 minutes for the trip. Thus, D is wrong, since it basically asserts that the personal trip is not the same as a delivery trip - it is conducted at different hours - so D weakens the conclusion that John needs the same amount of time to make his personal trip.

Note that we don't know whether he needs more or less than 80 minutes for his personal run at the different time, but we don't CARE - as long as we have reason to believe that the time taken will be different than the delivery's 80 minute average.

B does the same thing as D - it implies that a personal trip is not the same as delivery trip, and thus weakens the conclusion that the trips will take the same amount of time.

A and E attack the assumption that a singular trip today is the same as a 5 year average. In an average, some terms are greater than the average, and some are smaller. A and E show that the trip used to take longer than it does now, implying that the trip takes less than 80 minutes now to balance a total 5-year average of 80 minutes.

C is indeed the answer - the 80 minutes are given for the trip itself, excluding all other activities, which, presumable, John does not need to perform for his personal trip anyway. Thus, C does not give us any reason to suspect that his trip time will be different from the delivery's 80 minute time.

Thanx Geva. Point taken.