GMAT Question of the Day - Daily to your Mailbox; hard ones only

 It is currently 08 Dec 2019, 16:06

### GMAT Club Daily Prep

#### Thank you for using the timer - this advanced tool can estimate your performance and suggest more practice questions. We have subscribed you to Daily Prep Questions via email.

Customized
for You

we will pick new questions that match your level based on your Timer History

Track

every week, we’ll send you an estimated GMAT score based on your performance

Practice
Pays

we will pick new questions that match your level based on your Timer History

# In the vast majority of cases, when people are stopped by

Author Message
TAGS:

### Hide Tags

Intern
Joined: 10 Oct 2009
Posts: 19
In the vast majority of cases, when people are stopped by  [#permalink]

### Show Tags

19 Jan 2010, 02:08
1
1
00:00

Difficulty:

(N/A)

Question Stats:

82% (02:15) correct 18% (01:32) wrong based on 189 sessions

### HideShow timer Statistics

In the vast majority of cases, when people are stopped by airport security clearance, it is because they are carrying small bits of metal, such as coins, that cannot be used as weapons, but are large enough to be picked up by highly sensitive metal detectors. Since virtually everyone carries such pieces of metal, and the weapons that are smuggled onto planes are often not made of metal, highly sensitive metal detectors have outlived their usefulness. Lowering the sensitivity of these metal detectors so that they only detect large pieces of metal would reduce the frequency with which innocent passengers are stopped without hampering security’s ability to screen for weapons.

Which of the following, if true, is most useful to support the claim that this proposal would have its desired effect if it were carried out?

(A) Airport metal detectors, when set to higher levels of sensitivity, will not react to wristwatches, belt buckles, or the small rivets commonly used on travelers’ jeans.

(B) The maintenance and electricity costs associated with metal detectors are far lower when detectors are utilized at a high level of sensitivity than when they are used at a lower level of sensitivity.

(C) A metal detector with a low level of sensitivity can provide more information about what type of weapon a person is carrying, if they are carrying a weapon, than can a metal detector with a high level of sensitivity.

(D) In some cases, passengers who are stopped because they are only carrying coins are found to be smuggling non-metal weapons.

(E) Some weapons that are not made primarily out of metal include small bits of metal used as fasteners or serial number plates.
VP
Joined: 05 Mar 2008
Posts: 1340
Re: This CR really drives me Crazy!!! metal detectors  [#permalink]

### Show Tags

19 Jan 2010, 06:50
aniec wrote:
In the vast majority of cases, when people are stopped by airport security clearance, it is because they are carrying small bits of metal, such as coins, that cannot be used as weapons, but are large enough to be picked up by highly sensitive metal detectors. Since virtually everyone carries such pieces of metal, and the weapons that are smuggled onto planes are often not made of metal, highly sensitive metal detectors have outlived their usefulness. Lowering the sensitivity of these metal detectors so that they only detect large pieces of metal would reduce the frequency with which innocent passengers are stopped without hampering security’s ability to screen for weapons.

Which of the following, if true, is most useful to support the claim that this proposal would have its desired effect if it were carried out?

(A) Airport metal detectors, when set to higher levels of sensitivity, will not react to wristwatches, belt buckles, or the small rivets commonly used on travelers’ jeans.

(B) The maintenance and electricity costs associated with metal detectors are far lower when detectors are utilized at a high level of sensitivity than when they are used at a lower level of sensitivity.

(C) A metal detector with a low level of sensitivity can provide more information about what type of weapon a person is carrying, if they are carrying a weapon, than can a metal detector with a high level of sensitivity.

(D) In some cases, passengers who are stopped because they are only carrying coins are found to be smuggling non-metal weapons.

(E) Some weapons that are not made primarily out of metal include small bits of metal used as fasteners or serial number plates.

My guess is A
B. out of scope
C, D, E weaken the claim. They give reasons why sensitivity shouldn't be lowered.
Intern
Joined: 08 Nov 2009
Posts: 40
Re: This CR really drives me Crazy!!! metal detectors  [#permalink]

### Show Tags

19 Jan 2010, 08:48
Let's remember that we have to assume that the statements are true. We are asked for a statement that strenghtens the argument. The argument is: lowering the sensitivity of metal detectors will reduce the annoyance to passengers without negative impacts on security.

A) It says that metal detectors operating according to current practices do not pick up objects larger than coins, denying that they can pick up coins. Weakens, hence wrong answer.

B) The fact that the modification in operating levels carries negative consequences in terms of costs weakens the argument, hence wrong answer.

C) Lowering the level of sensitivity will make the detectors more powerful in picking up weapons (note: not necessarily METAL weapons!). This would result in a positive impact on security, which strenghtens the argument. Right Answer.

D) It says that although incidentally, current operating standards result in the discovery of actual weapons. Modifying the operating standards would prevent this from happening, with a negative effect on security. Weakens, hence wrong answer.

E) If non metal weapons carry metal bits, one would want to have very sensitive detectors to pick them up. Reducing sensitivity would result in a decrease in safety. Weakens, hence wrong answer.

VP
Joined: 05 Mar 2008
Posts: 1340
Re: This CR really drives me Crazy!!! metal detectors  [#permalink]

### Show Tags

19 Jan 2010, 12:16
The conclusion is:

"Lowering the sensitivity of these metal detectors so that they only detect large pieces of metal would reduce the frequency with which innocent passengers are stopped without hampering security’s ability to screen for weapons."

With A, the conclusion is strengthened. Passengers will not be burdened because a lower sensitivity will not pick up items commonly found on people going through the metal detector.
Intern
Joined: 08 Nov 2009
Posts: 40
Re: This CR really drives me Crazy!!! metal detectors  [#permalink]

### Show Tags

19 Jan 2010, 13:58
Re-reading answer A I suspect it might be the right one since it reinforces the successfulness of the program's goal.
Intern
Joined: 10 Oct 2009
Posts: 19
Re: This CR really drives me Crazy!!! metal detectors  [#permalink]

### Show Tags

20 Jan 2010, 02:54
Thanks guys!

OA is A.

But I still cannot fully understand why A is correct while C is wrong
Manager
Status: Its Wow or Never
Joined: 11 Dec 2009
Posts: 138
Location: India
Concentration: Technology, Strategy
GMAT 1: 670 Q47 V35
GMAT 2: 710 Q48 V40
WE: Information Technology (Computer Software)
Re: This CR really drives me Crazy!!! metal detectors  [#permalink]

### Show Tags

20 Jan 2010, 03:45
IMO C..do not understand how A can be the answer..

aniec wrote:
In the vast majority of cases, when people are stopped by airport security clearance, it is because they are carrying small bits of metal, such as coins, that cannot be used as weapons, but are large enough to be picked up by highly sensitive metal detectors. Since virtually everyone carries such pieces of metal, and the weapons that are smuggled onto planes are often not made of metal, highly sensitive metal detectors have outlived their usefulness. Lowering the sensitivity of these metal detectors so that they only detect large pieces of metal would reduce the frequency with which innocent passengers are stopped without hampering security’s ability to screen for weapons.

Which of the following, if true, is most useful to support the claim that this proposal would have its desired effect if it were carried out?

(A) Airport metal detectors, when set to higher levels of sensitivity, will not react to wristwatches, belt buckles, or the small rivets commonly used on travelers’ jeans. does nt guarantee that detectors will not detect coins..which seems to be the issue in the argument.

(B) The maintenance and electricity costs associated with metal detectors are far lower when detectors are utilized at a high level of sensitivity than when they are used at a lower level of sensitivity.cost is not an issue.

(C) A metal detector with a low level of sensitivity can provide more information about what type of weapon a person is carrying, if they are carrying a weapon, than can a metal detector with a high level of sensitivity. if lowering the sensitivity can better results why not do so.Seems correct to me.

(D) In some cases, passengers who are stopped because they are only carrying coins are found to be smuggling non-metal weapons.out of scope.

(E) Some weapons that are not made primarily out of metal include small bits of metal used as fasteners or serial number plates.out of scope.
Intern
Joined: 08 Nov 2009
Posts: 40
Re: This CR really drives me Crazy!!! metal detectors  [#permalink]

### Show Tags

20 Jan 2010, 11:08
I would explain the preference for answer A as follows:

the passage makes the following logical argument: Lower accuracy setting of metal detector -> less annoyance for passengers, no impact on security.

We have to try to reinforce THIS argument, not another one, regardless whether this other argument is valid or not.

A says the following: lower accuracy setting of metal detector -> less annoyance for passengers due to items that are not a security threats.

C says the following: lower accuracy setting of metal detector -> increased detection capabilities, hence more security.

The argument in C may be a more compelling one to make the transition, but does not directly support the argument made by the passage, while A does just that.
Manager
Joined: 24 Dec 2009
Posts: 152
Re: This CR really drives me Crazy!!! metal detectors  [#permalink]

### Show Tags

20 Jan 2010, 16:57
I agree A strengthens the argument that innocent passenger's pain will get reduced. However the proposal says of lowering the sensitivity while option A mentions about higher sensitivity metal detectors.

Can't understand answer as A. I would still think C as correct.
Senior Manager
Joined: 21 Jul 2009
Posts: 283
Schools: LBS, INSEAD, IMD, ISB - Anything with just 1 yr program.
Re: This CR really drives me Crazy!!! metal detectors  [#permalink]

### Show Tags

21 Jan 2010, 13:17
aniec wrote:
In the vast majority of cases, when people are stopped by airport security clearance, it is because they are carrying small bits of metal, such as coins, that cannot be used as weapons, but are large enough to be picked up by highly sensitive metal detectors. Since virtually everyone carries such pieces of metal, and the weapons that are smuggled onto planes are often not made of metal, highly sensitive metal detectors have outlived their usefulness. Lowering the sensitivity of these metal detectors so that they only detect large pieces of metal would reduce the frequency with which innocent passengers are stopped without hampering security’s ability to screen for weapons.

Which of the following, if true, is most useful to support the claim that this proposal would have its desired effect if it were carried out?

(A) Airport metal detectors, when set to higher levels of sensitivity, will not react to wristwatches, belt buckles, or the small rivets commonly used on travelers’ jeans.

(B) The maintenance and electricity costs associated with metal detectors are far lower when detectors are utilized at a high level of sensitivity than when they are used at a lower level of sensitivity.

(C) A metal detector with a low level of sensitivity can provide more information about what type of weapon a person is carrying, if they are carrying a weapon, than can a metal detector with a high level of sensitivity.

(D) In some cases, passengers who are stopped because they are only carrying coins are found to be smuggling non-metal weapons.

(E) Some weapons that are not made primarily out of metal include small bits of metal used as fasteners or serial number plates.

Impossible, I don't trust the source of this question. Clearly, "highly sensitive metal detectors have outlived their usefulness." is the conclusion of the entire stimulus. What follows next, "Lowering the sensitivity...blah...blah...blah" is like an additional premise, just adds to the discussion.

In this sense, definitely C should be the answer. C supports that lowering the sensitivity of the equipment also helps identifying the shape and size of the concealed weapon much better than a high sensitivity equipment, that clearlys seems to strengthen/support the claim that lowering sensitivity is for good. Add a new premise to an existing additional premise to strengthen the conclusion of the argument.
Manager
Joined: 21 Dec 2009
Posts: 125
Location: India
Re: This CR really drives me Crazy!!! metal detectors  [#permalink]

### Show Tags

22 Jan 2010, 05:13
What is the source ...even I think it is C.
_________________
Cheers,
SD
Intern
Joined: 10 Oct 2009
Posts: 19
Re: This CR really drives me Crazy!!! metal detectors  [#permalink]

### Show Tags

22 Jan 2010, 07:52
SudiptoGmat wrote:
What is the source ...even I think it is C.

Form Knewton free Diagnostic test
Manhattan Prep Instructor
Affiliations: ManhattanGMAT
Joined: 21 Jan 2010
Posts: 331
Location: San Francisco
Re: This CR really drives me Crazy!!! metal detectors  [#permalink]

### Show Tags

23 Jan 2010, 11:48
2
Hey All,

Just wanted to put my two cents in. I agree that the correct answer to this question ought to be C. Answer choice A confuses higher sensitivity and lower sensitivity. The question is whether or not LOWERING the sensitivity of the apparatus will have an effect, either through annoying passengers or failing to locate weapons. Answer choice A says that if the machine is set to HIGHER sensitivity, it won't pick up on rivets and such. Not only does this not make any sense (why would higher sensitivity NOT pick up those things?). It seems to me this question was perhaps copied incorrectly (here on the message board), and "higher" should be "lower". Answer choice C directly relates to the conclusion. OBVIOUSLY lowering the sensitivity will mean the machine picks up on fewer small objects, so we don't need our strengthen answer to address that. We just want to make sure it ALSO doesn't hamper the security abilities of the machine. Answer choice C tells us that this is the case.

Hope that helps!

Tommy Wallach
Knewton GMAT Representative
Joined: 23 Oct 2009
Posts: 111
Location: New York, NY
Schools: BA Amherst College, MFA Brooklyn College
Re: This CR really drives me Crazy!!! metal detectors  [#permalink]

### Show Tags

08 Jun 2010, 07:03
Thanks for the discussion everyone.

Your confusion is understandable since the question was actually copied incorrectly!

In our materials, answer choice A reads "(A) Airport metal detectors, when set to LOWER levels of sensitivity..."

And then the answer is clearly A (though C does remain a strong second-best option). Here's the whole explanation.

--
We are given a situation in which airport metal detectors are said to be too sensitive, forcing innocent passengers carrying coins to be stopped. The argument states that innocent passengers would be stopped less often (because the small bits of harmless metal they are carrying would not set off detectors) with no loss of security (because weapons are not always metal, and if they are, use a larger amount of metal than a coin) if the detectors were programmed to be less sensitive. The correct answer will be additional evidence that supports the first claim without undermining the second.

Choice A: This choice is correct. This choice bolsters the claim that passengers, presumably innocent, with small bits of metal that are not weapons (watches, belts or jean rivets) will not be stopped unnecessarily. Although this choice adds nothing to the claim that security will retain its ability to screen for weapons, it does not undermine it either.

Choice B: The cost of the proposed plan is not at issue. The desired effect of the plan is to retain security and reduce innocent passenger stops, and this choice does not effect either of those issues.

Choice C: This is a very tempting answer choice, because it is a positive aspect of low-sensitivity metal detectors, but this choice does not, in fact, directly address the claim that fewer innocent people will be stopped by the low-sensitivity detectors. This choice only applies to people already carrying weapons, who are not, by definition, innocent.

Choice D: This choice undermines the claim. If passengers who are stopped for having small amounts of metal are carrying weapons, then reducing security's ability to stop them would hamper the ability to screen for weapons.

Choice E: This choice also undermines the proposal. If only small pieces of metal are used in weapons, then a metal detector must be able to detect small pieces of metal to detect weapons.
Manhattan Prep Instructor
Affiliations: ManhattanGMAT
Joined: 21 Jan 2010
Posts: 331
Location: San Francisco
Re: This CR really drives me Crazy!!! metal detectors  [#permalink]

### Show Tags

09 Jun 2010, 11:01
Aha! Thanks for that correction, sir. I see now how A would be far better, given the right wording.

-tommy
Director
Joined: 16 Jul 2009
Posts: 707
Schools: CBS
WE 1: 4 years (Consulting)
Re: This CR really drives me Crazy!!! metal detectors  [#permalink]

### Show Tags

30 Jul 2010, 14:37
JoshKnewton wrote:
Thanks for the discussion everyone.

Your confusion is understandable since the question was actually copied incorrectly!

In our materials, answer choice A reads "(A) Airport metal detectors, when set to LOWER levels of sensitivity..."

And then the answer is clearly A (though C does remain a strong second-best option). Here's the whole explanation.

--
We are given a situation in which airport metal detectors are said to be too sensitive, forcing innocent passengers carrying coins to be stopped. The argument states that innocent passengers would be stopped less often (because the small bits of harmless metal they are carrying would not set off detectors) with no loss of security (because weapons are not always metal, and if they are, use a larger amount of metal than a coin) if the detectors were programmed to be less sensitive. The correct answer will be additional evidence that supports the first claim without undermining the second.

Choice A: This choice is correct. This choice bolsters the claim that passengers, presumably innocent, with small bits of metal that are not weapons (watches, belts or jean rivets) will not be stopped unnecessarily. Although this choice adds nothing to the claim that security will retain its ability to screen for weapons, it does not undermine it either.

Choice B: The cost of the proposed plan is not at issue. The desired effect of the plan is to retain security and reduce innocent passenger stops, and this choice does not effect either of those issues.

Choice C: This is a very tempting answer choice, because it is a positive aspect of low-sensitivity metal detectors, but this choice does not, in fact, directly address the claim that fewer innocent people will be stopped by the low-sensitivity detectors. This choice only applies to people already carrying weapons, who are not, by definition, innocent.

Choice D: This choice undermines the claim. If passengers who are stopped for having small amounts of metal are carrying weapons, then reducing security's ability to stop them would hamper the ability to screen for weapons.

Choice E: This choice also undermines the proposal. If only small pieces of metal are used in weapons, then a metal detector must be able to detect small pieces of metal to detect weapons.

But the conclusion has 2 points:
- Reduce the frequency with which innocent passengers are stopped.
- Not to hamper security’s ability to screen for weapons.

A addresses the first point, but not the second one; and C vice versa.

So, how you can say that A is better than C?
Thanks.
Manager
Joined: 23 May 2010
Posts: 212
Re: This CR really drives me Crazy!!! metal detectors  [#permalink]

### Show Tags

30 Jul 2010, 22:20
c....but now A ....not after correction but after reading the explantion
Manager
Joined: 02 Apr 2010
Posts: 51
Re: This CR really drives me Crazy!!! metal detectors  [#permalink]

### Show Tags

30 Jul 2010, 23:04
1
no wonder it doesn't make sense.
VP
Joined: 12 Dec 2016
Posts: 1487
Location: United States
GMAT 1: 700 Q49 V33
GPA: 3.64
Re: In the vast majority of cases, when people are stopped by  [#permalink]

### Show Tags

25 Jun 2017, 05:20
Senior Manager
Joined: 15 Jan 2017
Posts: 333
Re: In the vast majority of cases, when people are stopped by  [#permalink]

### Show Tags

17 Jul 2017, 22:35
TommyWallach wrote:
Hey All,

Just wanted to put my two cents in. I agree that the correct answer to this question ought to be C. Answer choice A confuses higher sensitivity and lower sensitivity. The question is whether or not LOWERING the sensitivity of the apparatus will have an effect, either through annoying passengers or failing to locate weapons. Answer choice A says that if the machine is set to HIGHER sensitivity, it won't pick up on rivets and such. Not only does this not make any sense (why would higher sensitivity NOT pick up those things?). It seems to me this question was perhaps copied incorrectly (here on the message board), and "higher" should be "lower". Answer choice C directly relates to the conclusion. OBVIOUSLY lowering the sensitivity will mean the machine picks up on fewer small objects, so we don't need our strengthen answer to address that. We just want to make sure it ALSO doesn't hamper the security abilities of the machine. Answer choice C tells us that this is the case.

Hope that helps!

Tommy Wallach

Hi with regards, to the post on why OA is A (I think because of the incorrect copying); my two observations are:
- C makes sense as it addresses the conclusion that highly sensitive weapons detector's have outlived there time
- A ALSO is right, but isn't that what the argument already says "lowering sensitivity = less nuisance for passengers"

So my question is - why is the conclusion of metal detectors being less useful incorrect?
Re: In the vast majority of cases, when people are stopped by   [#permalink] 17 Jul 2017, 22:35
Display posts from previous: Sort by