Just like for GMAT Reading Comprehension, correctly answering the questions for Critical Reasoning will require you to understand the passage fully. You’ll need to break it down, finding the conclusion, evidence, and assumptions for the argument. If you read the Q first, then go back to the passage and break it down, chances are you’ll have to re-read the Q to remember what it was specifically asking anyway. Better just to do the passage first, then the passage. That way you waste no time, and focus your attention where it should be — on the passage.
Try this practice question on your own!
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.
Here’s how we can break down this passage:
Conclusion: John should allow 80 min. for round trip.
Evidence: XYZ drivers average 80 min round trip (not including loading, unloading, or delivery)
Assumptions: There is no difference in the time in John’s car versus an XYX car. John won’t be loading, unloading or making deliveries.
Question Rephrase: What does NOT hurt the conclusion?
Prediction: Eliminating choices that WOULD hurt the conclusion – show that 80 min. would not be a good estimate.
A – Incorrect. If there is increasing traffic, it could slow John down.
B – Incorrect. This would mean John would probably be able to go faster.
C – Correct. While this fact seems irrelevant to John’s trip, it does NOT call into question the idea that John should allot 80 min. for his trip.
D – Incorrect. If there are fewer cars on the road, he’d probably be able to go faster.
E – Incorrect. If the 80 min. average was for all 5 years, but 2 years ago a highway was built, then John could probably go faster than the 80 min.
All of the choices except C would affect the time it takes John to travel; therefore (C) is correct.