|
Author |
Message |
|
TAGS:
|
|
|
Senior Manager
Joined: 10 Mar 2008
Posts: 378
Followers: 3
Kudos [?]:
18
[0], given: 0
|
A compelling optical illusion called the illusion of [#permalink]
 11 Jul 2008, 07:02
Question Stats:
54% (02:09) correct
45% (01:45) wrong based on 3 sessions
A compelling optical illusion called the illusion of velocity and size makes objects appear to be moving more
slowly the larger the objects are. Therefore, a motorist’s estimate of the time available for crossing a highway
with a small car approaching is bound to be lower than it would be with a large truck approaching.
The conclusion above would be more properly drawn if it were made clear that the
(A) truck’s speed is assumed to be lower than the car’s
(B) truck’s speed is assumed to be the same as the car’s
(C) truck’s speed is assumed to be higher than the car’s
(D) motorist’s estimate of time available is assumed to be more accurate with cars approaching than with trucks
approaching
(E) motorist’s estimate of time available is assumed to be more accurate with trucks approaching than with cars
approaching
|
|
|
|
|
|
|
Director
Joined: 10 Sep 2007
Posts: 958
Followers: 5
Kudos [?]:
152
[0], given: 0
|
Re: CR:optical illusion [#permalink]
11 Jul 2008, 07:14
IMO B.
Truck is heavier, so if car and truck run at same speed, truck will appear slower. Therefore driver from opposite side will estimate that car will quickly cross as compared to truck.
|
|
|
|
|
|
Manager
Joined: 02 May 2008
Posts: 88
Followers: 1
Kudos [?]:
12
[0], given: 0
|
Re: CR:optical illusion [#permalink]
11 Jul 2008, 07:36
Ans : B.
In all the other cases the conclusion drawn may not be true.
Lets say option A was true.
In this case since the truck is slower than the car it will in any case take more time to reach the motorists irrespective of other factors like illusion of velocity or size.
|
|
|
|
|
|
Director
Joined: 25 Oct 2006
Posts: 656
Followers: 7
Kudos [?]:
104
[0], given: 6
|
Re: CR:optical illusion [#permalink]
11 Jul 2008, 08:58
Premise: due to illusion - object size makes objects appear to be moving more slowly. Conclusion: time to cross car is less than time to cross truck. Hence Car takes less time while truch takes more time to cover the distance. A. if truck's speed is less, it is not illusion - Can not be the answer B. If speeds are same, illusion acts - Answer C. again Speed should be constant D and E: Accuracy of Motorist's estimation is not be considered as we are making relation between illusion and time while speed is contant.
_________________
If You're Not Living On The Edge, You're Taking Up Too Much Space
|
|
|
|
|
|
Senior Manager
Status: MBAing!!!!
Joined: 24 Jun 2011
Posts: 314
Location: United States (FL)
Concentration: Finance, Real Estate
Schools: Wharton '14 (D), CBS '14 (WL), Ross '14 (WL), Haas '14 (D), Johnson '14 (A), McCombs '14, Kenan-Flagler '14 (M), Madison (A), Consortium (D), Consortium (A), Consortium (M), Consortium, Consortium (A), Consortium (WL)
GPA: 3.65
WE: Project Management (Real Estate)
Followers: 5
Kudos [?]:
41
[0], given: 56
|
Re: CR:optical illusion [#permalink]
26 Oct 2011, 12:57
I picked B...that is the correct assumption to arrive to that conclusion.
|
|
|
|
|
|
Intern
Joined: 27 Jan 2011
Posts: 29
Followers: 0
Kudos [?]:
3
[0], given: 0
|
Re: CR:optical illusion [#permalink]
27 Oct 2011, 14:50
"B". Assumption has to be tied to the premise (illusion) to arrive at the conclusion.
|
|
|
|
|
|
Manager
Joined: 11 Jul 2009
Posts: 120
Location: India
WE: Design (Computer Software)
Followers: 1
Kudos [?]:
7
[0], given: 13
|
Re: CR:optical illusion [#permalink]
28 Oct 2011, 04:19
B..
_________________
Kaustubh
|
|
|
|
|
|
Verbal GMAT Forum Moderator
Status: Flying over the cloud!
Joined: 17 Aug 2011
Posts: 787
Location: Viet Nam
Concentration: International Business, Finance
GPA: 3.07
Followers: 18
Kudos [?]:
80
[0], given: 35
|
Re: A compelling optical illusion called the illusion of [#permalink]
16 Dec 2011, 03:34
|
|
|
|
|
|
Manager
Joined: 07 Aug 2011
Posts: 186
Location: United States
Concentration: Technology, International Business
GMAT 1: 690 Q48 V37
Followers: 3
Kudos [?]:
20
[0], given: 6
|
Re: A compelling optical illusion called the illusion of [#permalink]
26 Dec 2011, 11:46
B
|
|
|
|
|
|
Manager
Joined: 28 Sep 2011
Posts: 206
Followers: 1
Kudos [?]:
14
[0], given: 5
|
Re: A compelling optical illusion called the illusion of [#permalink]
24 Mar 2012, 18:36
I have chosen B for this question:
The optical illusion is only true if the 2 objects are moving at the same speed.
A. This is not an assumption made by the argument. If the truck's speed is slower, then what is the point of the optical illusion? Clearly, if the truck is moving slower, the motorist will have more time.
B. This is the correct answer. We have a good comparison now because we are comparing 2 objects moving at the same speed, so the larger truck will appear to be moving slower than the small car.
C. Same as A but reversed
D. How can we assume this? Nothing in the passage mentions the motorist's ability to estimate time.
E. Same as E.
|
|
|
|
|
|
Manager
Joined: 03 Aug 2011
Posts: 55
Followers: 1
Kudos [?]:
5
[0], given: 3
|
Re: A compelling optical illusion called the illusion of [#permalink]
25 Mar 2012, 02:14
The answer should be B.
because only if we assume, both of the vehicles move at the same speed, we can make the conclusion valid.
|
|
|
|
|
|
Intern
Joined: 05 Mar 2013
Posts: 15
GMAT Date: 04-20-2013
Followers: 0
Kudos [?]:
0
[0], given: 9
|
Re: A compelling optical illusion called the illusion of [#permalink]
13 Apr 2013, 17:39
Blue Book CR67
Strengthen
Conclusion: Estimated that small car takes LESS time than large truck. Why?
Premise: (On the basis of illusion of v and s) Appeared that larger objects to have less speed, thus incurred more time.
Not A: If assumed that truck's speed less than car, then estimation is not necessary since the case presents that it must always be true that car will take LESS time.
It's B: If assumed that truck's speed is same as car (holding all other factors, in this case is velocity, constant), this is in accordance with the illusion theory that the estimation is based on the appearance that car takes LESS time than large truck.
Last edited by margaretgmat on 13 Apr 2013, 18:31, edited 1 time in total.
|
|
|
|
|
|
Manager
Status: Looking to improve
Joined: 15 Jan 2013
Posts: 102
GMAT 1: 530 Q43 V20
GMAT 2: 560 Q42 V25
GMAT 3: 650 Q48 V31
Followers: 1
Kudos [?]:
10
[0], given: 30
|
Re: A compelling optical illusion called the illusion of [#permalink]
13 Apr 2013, 18:14
IMHO answer is B. This question type is a find the assumption, which must be true otherwise the conclusion falls apart. The conclusion is motor estimate when looking at small car is smaller than when looking at bigger truck and this is because of optical illusion. B is the only answer which destroys the conclusion if negated - The speed of approaching car and truck are not the same.. //kudos please, if this explanation is good.
_________________
KUDOS is a way to say Thank You
|
|
|
|
|
|
|
Re: A compelling optical illusion called the illusion of
[#permalink]
13 Apr 2013, 18:14
|
|
|
|
|
|
|
|
|
|
Moderators:
metallicafan, rajeevrks27, souvik101990, PTK, MacFauz, noboru, kissthegmat, carcass, willigetmylifeback, mikemcgarry, doe007, Vercules, Legendaddy, tuanquang269, RaviChandra, Marcab, Narenn
|
close
