In their search for Mayan ruins in the jungles of Guatemala, archaeolo

Yes, you're absolutely right. If a conclusion has the structure "If X is true, then Y is true", then you're never assuming that X is actually true (or possible, or practical).

If I say: "If a plane could travel at 41,000 km per hour, it could circle the Earth in one hour", that's almost an airtight conclusion (the circumference of the Earth is roughly 40,000 km). I'm assuming a few unimportant things - that such a plane could travel roughly in a straight line, that it could maintain that speed for an hour, etc. But I'm definitely not assuming that such a plane could be built. You can rephrase that conclusion to better see its structure: "If we assume it is true that a plane can travel at 41,000 km per hour, then that plane could travel around the Earth in one hour." It's easier to see with this phrasing that "a plane can travel at 41,000 km/hr" effectively becomes a premise of the conclusion -- the conclusion is only relevant if that premise is true, so it can't be "wrong". We're never making any kind of assumption about whether that premise is true or false or possible or impossible.

In this satellite question, the conclusion essentially says "if satellites could use infrared cameras, they'd find Mayan ruins". That conclusion is assuming it is possible to equip satellites with infrared technology, and declaring what the consequences would then be. The conclusion is absolutely not assuming anything about how practical it is to equip satellites with infrared cameras. So we don't care if there's funding to upgrade the satellites, and we also don't care if infrared cameras are compatible with current satellites.

This question, like many other prep company CR questions, has two right answers, B and E. There's no way to decide between them, since they're both clearly not assumptions.

I should comment on the distinction some posts above are making between answers B and E. The conclusion here says roughly "If satellites can be equipped with infrared cameras, then..." That is different from saying "If satellites in orbit could use infrared cameras to photograph Mayan ruins..." It's not enough simply to "equip" satellites with cameras; the satellites need to be able to use them. So the argument is assuming things like "the cameras don't cause the satellites to explode" and "the satellites can train the cameras on the relevant location" and "there is a way to get a satellite up in the sky that has these infrared cameras on board". It's on that basis that some replies above are taking E to be an assumption - it might be possible to "equip" a satellite with a camera, but if it's not possible to get that satellite into space, the conclusion is false. But that's not what answer E says -- the language of answer E is far more specific. We're not specifically assuming we can equip a satellite on earth with the camera and then send that satellite to space. Maybe we can send an astronaut to space and she can upgrade a currently orbiting satellite with the technology; then we don't need to assume funds are available to "launch" anything. As it's worded, E is no more an assumption than B.

As you said yourself, IFwe can equip or not is not pertinent. So, it doesn't matter IF we can equip the current satellites with the new technology. The conclusion is based on a conditional statement: "If scientists can equip satellites with this new infrared imaging technology." We don't care whether the condition can actually be met. Thus, choice (B) has no impact on the conclusion.

Let's assume that condition is met and we CAN equip a satellite with the technology. Great, but what if we can't afford to actually send the thing into space? In that case, our satellite will just sit sadly in the lab and won't help discover any ruins. Thus, choice (E) is actually required.

I think you have the right idea here...

• The conclusion involves a hypothetical situation: IF it is possible for scientists to equip satellites with this new infrared imaging technology, THEN...
• It doesn't matter whether scientists actually CAN equip satellites with the new technology. But IF they can, THEN, according to the argument, the discovery of Mayan ruins in the jungles of Guatemala will surely be expedited.
• So, yes, because of the conditional nature of the conclusion, (B) is not a required assumption.

I hope that helps!

You're right: we don't know whether the new technology will be applied to a new satellite or an existing one. But, in order for the conclusion to hold, we need at least ONE satellite, new or old, to be equipped with the new tech and launch (or relaunched?) into space. So (E) is required.

Choice (B) could be true, but it is not required. For example, the new infrared imaging technology might NOT compatible with satellites currently used to photograph the Earth from space. But the argument could still hold if the new tech can be installed in new/different satellites.

Again, choice (B) could be true, but the argument and conclusion could still hold even if (B) is not true. So that makes (B) our winner.

(C) is not saying that we need to be able to distinguish between the ruins of one place and the ruins of another place. Instead, (C) states that we must be able to distinguish between two different types of heat signatures: (1) those of undiscovered Mayan ruins and (2) those of the jungles surrounding the ruins. In other words, (C) says that we need to be able to distinguish between the heat signatures of RUINS and JUNGLE.

As we said in our previous post, if the heat signatures of the ruins and the jungle are the same, then the ruins and the jungle will look the same on the satellite images. This means that we won’t be able to learn anything from those images. For that reason, (C) must be true in order for the conclusion to be properly drawn, and we can eliminate it.

I hope that helps!

We have been given this condition : If scientists can equip satellites with this new infrared imaging technology

so our analysis starts after we can equip the satellite. If we can equip or not is not pertinent.
That's why E should be the correct answer.

Why B is wrong?
B) The new infrared imaging technology is compatible with satellites currently used to photograph the Earth from space.


It is given that "archaeologists have recently been able to discern some Mayan ruins in photographs taken from helicopters flown just above the tree canopy" so in this situation and the situation we are evaluating, what is the difference? what has changed? Helicopters to satellite. We don't know if this technology is also compatible with satellite or not. if it is not then then surely conclusion falls apart, hence B is one of the correct assumption here.

Further: https://gmatclub.com/forum/the-number-o ... ml?kudos=1


(C) Country X does not have the resources to examine all visitors from Country Y.
is not the answer precisely for the same reason.

My concern is that the passage only talks about equipping the satelite with the infrared tech. Nothing about where the equipping is going to be done or whether it'll be a new satelite or one that is already in space. How can we then base our answer choice on the fact that the the equipping will happen only on a new satelite?

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Dear IanStewart

I would much appreciate, if you could comment on my reasoning below.

First, could you please take a look at this post here :



The above-quoted argument that GMATNinja uses to opt for B can also be used for E.

(E) Funds will be available to cover the cost of launching at least one satellite with the new infrared imaging technology into orbit.

As the highlighted sentence above claims, because of the conditional nature of the conclusion, we do NOT care whether scientists ACTUALLY can equip satellites with the new technology. What we care is what would happen AFTER satellites are equipped. So, those obstacles (either technical as in B or financial as in E) that emerge BEFORE satellites are equipped should not be considered. i.e., Because the conclusion says “if scientists CAN equip…”, we can safely infer that we are dealing with the hypothetical situation in which scientists have already done so despite any probable obstacles. Hence, E is not a required assumption.

Moreover, the negation of the required assumption should render the conclusion invalid, and turn it into: “EVEN WHEN equipped with new technology, satellites will NOT necessarily expedite the discovery”. However, the negation of E fails to do so. Hence, E is not a required assumption.

Thank you very much for your time and consideration!

Dear experts/GMATNinja,

I am not able to understand how option C is the incorrect choice. The argument specifically tells us that the act of finding the ruins is happening in the jungles of place X.

Should we care if the heat signatures of ruins at place X matches with those at neighboring places? We are concerned with the fact that are we able to detect the heat signatures of ruins at place X. If yes, then ruins will be found and if not, then we won't be able to fins the ruins - by infrared or by satellite imagery.

Kindly explain why C must be an assumption.

I completely agree. I think option B and option E are opposites of each other and choosing among the 2 is akin to tossing a coin in the air.
We already know why option B can be an exception. Option E states that we have the funds needed to launch a new satellite that is equipped with the new tech into the atmosphere. But what if we do not require to launch a satellite into the atmosphere. Maybe the new tech can be hardwired into the already existing satellites at a much cheaper cost. This is similar to what is mentioned in option B. The logical thinking between both the options absolutely mirror each other. I think there needs to be some modification in the question to help clear one of the options. Would request some help in this question.

What about the case where they do not have money to launch a new satellite but they could still equip an existing satellite in orbit with this new technology?
GMATNinja

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