vbetanabhatla wrote:
Here is a
MGMAT question that I got in my CAT test. I want to believe
MGMAT knows (way!!!) more about CR than I do. But I can't understand their logic on this question. Can someone please enlighten me?
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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?
A) 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.
B) Most of XYZ’s courier vehicles are heavy trucks, for which speed limits are lower than for passenger vehicles.
C) 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.
D) John will make his personal trip at an hour when XYZ does not make delivery trips.
E) 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.
John's conclusion - it should take same amount of time for his personal trip as it does for the deliveries.
Question - Which one does NOT WEAKEN John's conclusion.
A) The average time taken over the past five years has been 80 minutes. The population and congestion also has increased over the past five years. Worst case scenario - population stayed the same over 4 out of 5 years, but doubled just last year. So, say it used to take 40 minutes before and now takes about 120 minutes to deliver. Then it may weaken John's estimates that he can complete the trip in 80 minutes.
B) Delivery trucks are heavy and slow. Then they take more time than John's car to reach the destination. John would make the trip in less than 80 minutes. This strengthens his conclusion.
C) We know that the time taken for loading and unloading is not taken into consideration while calculating average delivery time for the company. This neither strengthens, nor weakens John's conclusion.
D) We don't know for sure what the consequences of this is going to be. If John is making personal trip at a busier hour, he would need more time, if not, he may complete the trip in less than 80 minutes. This can be viewed as an outside the scope option.
E) This means it used to take more than 80 minutes the first three years of the last five years, now it takes less. So, John would be able to complete the trip in less than the average time of 80 minutes.
Only (C) does NOT WEAKEN the conclusion and hence the right answer.
Hope this helps.