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

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Mo2men: Legendary Member; Posts: 712; Joined: Fri Sep 25, 2015 4:39 amFollowed by: 5 members; Thanked: 14 times

by Mo2men » Sun Nov 19, 2017 11:24 am

In their search for Mayan ruins in the jungles of Guatemala, archaeologists have been unable to utilize satellite imagery, which is taken by satellites that orbit 500 or more kilometers above the Earth's surface and cannot penetrate the dense tree canopy of the jungles. However, using new infrared imaging technology, which translates heat signatures into distinct colors, archaeologists have recently been able to discern some Mayan ruins in photographs taken from helicopters flown just above the tree canopy. If scientists can equip satellites with this new infrared imaging technology, the discovery of Mayan ruins in the jungles of Guatemala will surely be expedited.

The conclusion above logically depends on each of the following assumptions EXCEPT:

(A) All of the Mayan ruins in the jungles of Guatemala have not already been discovered.
(B) The new infrared imaging technology is compatible with satellites currently used to photograph the Earth from space.
(C) Some of the heat signatures of undiscovered Mayan ruins in the jungles of Guatemala are different from those of the surrounding jungle.
(D) The effectiveness of the new infrared imaging technology is not limited to photographs taken at heights just above the tree canopy.
(E) Funds will be available to cover the cost of launching at least one satellite with the new infrared imaging technology into orbit

OA: B
Dear GMATGuru

can you please share your thoughts in how to solve the above question?
Can you help with how E could be an assumption?

Thanks

Source: Beat The GMAT — Critical Reasoning | Sun Nov 19, 2017 11:24 am

GMATGuruNY: GMAT Instructor; Posts: 15539; Joined: Tue May 25, 2010 12:04 pmFollowed by: 1906 members; Location: New York, NY; Thanked: 13060 times; GMAT Score:790

Mayan ruins

by GMATGuruNY » Fri Nov 24, 2017 4:06 am

Mo2men wrote:In their search for Mayan ruins in the jungles of Guatemala, archaeologists have been unable to utilize satellite imagery, which is taken by satellites that orbit 500 or more kilometers above the Earth's surface and cannot penetrate the dense tree canopy of the jungles. However, using new infrared imaging technology, which translates heat signatures into distinct colors, archaeologists have recently been able to discern some Mayan ruins in photographs taken from helicopters flown just above the tree canopy. If scientists can equip satellites with this new infrared imaging technology, the discovery of Mayan ruins in the jungles of Guatemala will surely be expedited.

The conclusion above logically depends on each of the following assumptions EXCEPT:

(A) All of the Mayan ruins in the jungles of Guatemala have not already been discovered.
(B) The new infrared imaging technology is compatible with satellites currently used to photograph the Earth from space.
(C) Some of the heat signatures of undiscovered Mayan ruins in the jungles of Guatemala are different from those of the surrounding jungle.
(D) The effectiveness of the new infrared imaging technology is not limited to photographs taken at heights just above the tree canopy.
(E) Funds will be available to cover the cost of launching at least one satellite with the new infrared imaging technology into orbit

Plan: Equip satellites with new infrared imaging technology, which translates heat signatures into distinct colors.
Conclusion: The discovery of Mayan ruins in the jungles of Guatemala will surely be expedited.

To expedite means TO SPEED UP.
Apply the NEGATION TEST.
When the four of the answer choices are negated, they will invalidate the conclusion that -- once satellites have been equipped with the new technology -- the discovery of Mayan ruins will be SPED UP.
Eliminate these four answer choices.

(A) All of the Mayan ruins in the jungles of Guatemala have already been discovered.
Here, the discovery of Mayan ruins will be NOT be sped up, since all of the ruins have already been discovered.
Eliminate A.

(C) None of the heat signatures of undiscovered Mayan ruins in the jungles of Guatemala are different from those of the surrounding jungle.
Here, the discovery of Mayan ruins will be NOT be sped up, since it will be impossible to distinguish the heat signatures of Mayan ruins from those of the surrounding jungle.
Eliminate C.

(D) The effectiveness of the new infrared imaging technology is limited to photographs taken at heights just above the tree canopy.
Here, the discovery of Mayan ruins will be NOT be sped up, since the technology will be ineffective when attached to a satellite located far above the tree canopy.
Eliminate D.

(E) No funds will be available to cover the cost of launching at least one satellite with the new infrared imaging technology into orbit.
Here, the discovery of Mayan ruins will be NOT be sped up, since no funds will be available to launch even one satellite equipped with the new technology.
Eliminate E.

The correct answer is B.

B, negated:
The new infrared imaging technology is incompatible with satellites currently used to photograph the Earth from space.
The conclusion that the discovery of Mayan ruins will be sped up is based upon the PREMISE that satellites will be equipped with the new technology.
In stating that the new technology is incompatible with current satellites, the negation of B attempts to weaken this premise.
A premise cannot be weakened.
Since the negation of B weakens not the conclusion but a PREMISE, B does not constitute an assumption.

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