Find the Detail on GMAT Reading Comprehension
Ive got another installment for you in the series on the Meteor Stream passage from the free set of practice questions that comes with the GMATPrep software.
This post contains the 4th of 5 questions that come with the passage. If you havent already, go read the first article (linked in the first paragraph); Im not going to reproduce the full passage here because its so long. When youre done, keep that passage open in another window and come back here. (Note: you can try the other questions first if you like, or you can come straight back here. Your choice.)
Ready for the question? Give yourself about 1.5 minutes to answer.
The Question
According to the passage, why do the dust particles in a meteor stream eventually surround a comets original orbit?(A) They are ejected by the comet at differing velocities.
(B) Their orbits are uncontrolled by planetary gravitational fields.
(C) They become part of the meteor stream at different times.
(D) Their velocity slows over time.
(E) Their ejection velocity is slower than that of the comet.
The Solution
First, identify the question type. According to the passage signals that this is a specific detail question. Youre going to have to find some specific detail in the passage and spit it back to answer the question.
Next, find the proof in the passage. Re-read the relevant text and try to formulate your own answer to the question.
Which paragraph talked about dust particles in the meteor stream?
Paragraph three was the whole model vs. reality thing. Paragraph two talks about how the model works. Paragraph one was the one that actually got into the details of the meteor stream.
Head over to the passage and think about how to answer this question while scanning the text for keywords dust particles or original orbit. It's right at the beginning:
A meteor stream is composed of dust particles that have been ejected from a parent comet at a variety of velocities. These particles follow the same orbit as the parent comet, but due to their differing velocities they slowly gain or fall behind the disintegrating comet until a shroud of dust surrounds the entire cometary orbit.
Put the message in your own words: the dust particles get ejected, but they still follow along with the comet. They have different velocities, though, so they end up spreading out around the orbit.
So why do the dust particles in a meteor stream eventually surround a comets original orbit? Because the different velocities make them spread out in a cloud.
Okay, time to eliminate wrong answers and look for the right one!
(A) They are ejected by the comet at differing velocities.
Bingo. This matches the predicted answer: the different velocities cause the particles to spread out. This is the correct answer.
(B) Their orbits are uncontrolled by planetary gravitational fields.
The third sentence of the first paragraph does mention planetary gravitational fields. But it talks about how the dust particles orbit might be perturbed, or disrupted, by these fields, not why the particles surround the comets orbit in the first place.
(C) They become part of the meteor stream at different times.
I think this one can be really tricky because you might imagine that this is the reason. It makes sense logically that this would happen at different times. However, the passage doesnt actually say anything about this.
(D) Their velocity slows over time.
This one is tempting because the passage does mention velocity, but it talks about differing velocities, not necessarily whether the particles are speeding up or slowing down (or maintaining a steady speed).
(E) Their ejection velocity is slower than that of the comet.
Ejection velocity sounds good, too! The first sentence does say that these particles are ejected at different velocities. The next sentence, though, says that the particles slowly gain or fall behind the comet. This implies that some might be slower than the comet but others are faster, so this statement isnt true of all of the particles. It also isnt why the particles eventually surround the orbit. The passage states that this is due to the different velocities.
The correct answer is (A).
Were you tempted by one of the other answers? Heres how to learn from the trap that the test writers were setting for you.
First, articulate why you thought that wrong answer was (or might be) right. For instance, answer (E) matches some detail language closely (ejection velocity), so that would likely catch your eye.
Next, articulate why that answer was actually wrong. In this case, the passage specifically cites a variety of velocities as the cause, not just slower velocities.
Finally, articulate why the right answer seemed like it could be wrong, and then dont forget to articulate why its actually right. Answer (A) may not look as good as (E) because it doesnt feature that language match from the passage. Answer (A) says differing velocities instead of a variety of velocities. These two phrases are synonyms, thoughthey mean the same thing!
Key Takeaways for RC Specific Detail Questions
(1) Make sure you go back to the passage to find the proof. As much as you can, try to predict (in your own words!) what the correct answer should say before you read through the five answers. This will help you to understand the meaning that you need, and youll be less likely to fall for a false language match trap, as described above.
(2) For all verbal questions (not just RC!), analyze the problem when youre done. If you were tempted by a wrong answer, ask yourself 4 things: (1) Why did this answer look good (even though its wrong)? (2) Why is it actually wrong? (3) Why did the right answer not look good in some way (ie, why would I consider crossing it off)? (4) Why is the right answer right?
* GMATPrep text courtesy of the Graduate Management Admissions Council. Usage of this question does not imply endorsement by GMAC.
This article is part of a Reading Comprehension series. Check out the other entries below: