1. Craters are found most in geologically stable regions
2. This is due to lower rates of destructive forces in those areas

The question wants you to find the assumption that must occur in order for point 2 to be a valid conclusion

A. Incorrect. This has nothing to do with abundance of craters

B. Incorrect. If the rates vary this will probably cast doubt on the conclusion

C. Incorrect. Time is not a consideration

D. Correct. If the meteor impacts are not spaced evenly then there could be another reason that the craters are denser in certain spots. Imagine that maybe one of the areas with alot of craters gets hit 40 times a year by meteors while the other area gets hit only 5 times. Clearly the 40 hit location is going to have more craters and it will have nothing to do with the other geophysical forces in the area. For the forces to play a role all areas must see around the same amount of hits.

E. Incorrect. How often the areas are studied has nothing to do with the conclusion. How much they are studied does not effect the fact that there are more craters in certain locations.

fitzgerald23, thanks

I agree with D, but I think that E is ok as well. My reason is follows

We have two regions: the Stable one (S) and the non-stable one (NS). In addition we have "securely identified crater" (SIC) which are more applicable to S (where "lower rates of destructive geophysical processes") than to NS.

Let's take E and apply denial test. That if NS were NOT studied enough? This may result in the situation that guys did not find SIC (but actually the number of SIC is the same in S and NS). So E is the assumption as well.

Please correct my reasoning.

kvitkod wrote:fitzgerald23, thanks

I agree with D, but I think that E is ok as well. My reason is follows

We have two regions: the Stable one (S) and the non-stable one (NS). In addition we have "securely identified crater" (SIC) which are more applicable to S (where "lower rates of destructive geophysical processes") than to NS.

Let's take E and apply denial test. That if NS were NOT studied enough? This may result in the situation that guys did not find SIC (but actually the number of SIC is the same in S and NS). So E is the assumption as well.

Please correct my reasoning.

One of the most important things I learned when preparing for the GMAT and what made my verbal sc one jump from the low to mid 30s to the mid 40s is that you can never make any assumptions in these GMAT questions. You have to try to take them as literal as possible, which is very hard, especially when you get a question about something you are familiar with or something that seems like a logical conclusion.

In choice E you can probably make the logical leap that the studying is abot craters but it doesnt spell out what they are studying. Its one of those tricks that the GMAT does. You read a passage about craters so you assume that the studying is about craters. But does it say that is what it is about? No. Maybe they just studied rocks. Maybe they studied soil. Who knows. Unless the GMAT makes it pretty explicit dont draw a conclusion about what you are reading unless there is no other decent answer choice/

Now here is the other problem with E. Lets go back to the argument. The argument is that the amount of geophysical forces are causing craters to remain or disappear. If a region has less forces they will have more craters. Now what does E actually say. If we assume the study is about craters they are saying that the stable reasons have been studied more thoroughly. If that is true the reason more craters might be found is simply the fact that more people looked there. So it actually undermines the conclusion that its the forces causing it, because it is now introducing another reason why the craters were not found in less stable areas.

fitzgerald23, many thanx! it is really helpful!

fitzgerald23 wrote:

kvitkod wrote:fitzgerald23, thanks

I agree with D, but I think that E is ok as well. My reason is follows

We have two regions: the Stable one (S) and the non-stable one (NS). In addition we have "securely identified crater" (SIC) which are more applicable to S (where "lower rates of destructive geophysical processes") than to NS.

Let's take E and apply denial test. That if NS were NOT studied enough? This may result in the situation that guys did not find SIC (but actually the number of SIC is the same in S and NS). So E is the assumption as well.

Please correct my reasoning.

One of the most important things I learned when preparing for the GMAT and what made my verbal sc one jump from the low to mid 30s to the mid 40s is that you can never make any assumptions in these GMAT questions. You have to try to take them as literal as possible, which is very hard, especially when you get a question about something you are familiar with or something that seems like a logical conclusion.

In choice E you can probably make the logical leap that the studying is abot craters but it doesnt spell out what they are studying. Its one of those tricks that the GMAT does. You read a passage about craters so you assume that the studying is about craters. But does it say that is what it is about? No. Maybe they just studied rocks. Maybe they studied soil. Who knows. Unless the GMAT makes it pretty explicit dont draw a conclusion about what you are reading unless there is no other decent answer choice/

Now here is the other problem with E. Lets go back to the argument. The argument is that the amount of geophysical forces are causing craters to remain or disappear. If a region has less forces they will have more craters. Now what does E actually say. If we assume the study is about craters they are saying that the stable reasons have been studied more thoroughly. If that is true the reason more craters might be found is simply the fact that more people looked there. So it actually undermines the conclusion that its the forces causing it, because it is now introducing another reason why the craters were not found in less stable areas.

hey fitz , the conclusion talks about securely identified craters and (D) talks about meteoric impacts .
What distinguishes a meteor impact from a securely identified crater.
I understand the literal meanings of the 2 terms but when it comes to closing the gap between the premise and the conclusion , i need to make out the significance of the terms . As i said the conclusion talks about craters and the correct ans talks about impacts.

mundasingh123 wrote:[quote="fitzgerald23hey fitz , the conclusion talks about securely identified craters and (D) talks about meteoric impacts .
What distinguishes a meteor impact from a securely identified crater.
I understand the literal meanings of the 2 terms but when it comes to closing the gap between the premise and the conclusion , i need to make out the significance of the terms . As i said the conclusion talks about craters and the correct ans talks about impacts.

If you go back to line 1 the passage states that craters are caused by meteors. To have the crater you need the meteor. By securely identified I believe all they mean is that a crater has been found by a reputable source. D tells us that there should be a similar amount of craters in all areas. The fact that they are not found means something is making the craters vanish.

Conclusion: Lower rates of X resulted in high count in Y
X - geophysical processes
Y - craters

Premise 1: craters are found all around the globe.
Premise 2: Count is more on Stable regions.

The word "evenly" to premise 1 can help.
Geophysical process have covered the craters in non-stable regions.