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

It is currently 14 Dec 2018, 05:17

Close

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
Your Progress

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

Not interested in getting valuable practice questions and articles delivered to your email? No problem, unsubscribe here.

Close

Request Expert Reply

Confirm Cancel
Events & Promotions in December
PrevNext
SuMoTuWeThFrSa
2526272829301
2345678
9101112131415
16171819202122
23242526272829
303112345
Open Detailed Calendar

The figure below represents a track with identical semi-circular ends

  new topic post reply Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
TAGS:

Hide Tags

Math Expert
User avatar
V
Joined: 02 Sep 2009
Posts: 51214
The figure below represents a track with identical semi-circular ends  [#permalink]

Show Tags

New post 06 Oct 2014, 07:47
9
48
00:00
A
B
C
D
E

Difficulty:

  85% (hard)

Question Stats:

61% (03:38) correct 39% (03:20) wrong based on 493 sessions

HideShow timer Statistics

Tough and Tricky questions: Distance/Rate .



The figure below represents a track with identical semi-circular ends used for a 4-lap relay race involving two 4-person teams (where each team member runs one complete lap around the track). The table below shows the lap times for each runner on Team A and Team B. Assuming that each runner runs at a constant rate, Team A win the race by how many meters?
Image

A. 40 meters

B. \((40 + 10\pi)\) meters

C. \((40 + 20\pi)\) meters

D. \((20 + 10\pi)\) meters

E. \((20 + 20\pi)\) meters

Attachment:
Untitled.png
Untitled.png [ 26.39 KiB | Viewed 17326 times ]

_________________

New to the Math Forum?
Please read this: Ultimate GMAT Quantitative Megathread | All You Need for Quant | PLEASE READ AND FOLLOW: 12 Rules for Posting!!!

Resources:
GMAT Math Book | Triangles | Polygons | Coordinate Geometry | Factorials | Circles | Number Theory | Remainders; 8. Overlapping Sets | PDF of Math Book; 10. Remainders | GMAT Prep Software Analysis | SEVEN SAMURAI OF 2012 (BEST DISCUSSIONS) | Tricky questions from previous years.

Collection of Questions:
PS: 1. Tough and Tricky questions; 2. Hard questions; 3. Hard questions part 2; 4. Standard deviation; 5. Tough Problem Solving Questions With Solutions; 6. Probability and Combinations Questions With Solutions; 7 Tough and tricky exponents and roots questions; 8 12 Easy Pieces (or not?); 9 Bakers' Dozen; 10 Algebra set. ,11 Mixed Questions, 12 Fresh Meat

DS: 1. DS tough questions; 2. DS tough questions part 2; 3. DS tough questions part 3; 4. DS Standard deviation; 5. Inequalities; 6. 700+ GMAT Data Sufficiency Questions With Explanations; 7 Tough and tricky exponents and roots questions; 8 The Discreet Charm of the DS; 9 Devil's Dozen!!!; 10 Number Properties set., 11 New DS set.


What are GMAT Club Tests?
Extra-hard Quant Tests with Brilliant Analytics

Most Helpful Community Reply
SVP
SVP
User avatar
Status: The Best Or Nothing
Joined: 27 Dec 2012
Posts: 1825
Location: India
Concentration: General Management, Technology
WE: Information Technology (Computer Software)
Re: The figure below represents a track with identical semi-circular ends  [#permalink]

Show Tags

New post 10 Oct 2014, 21:01
28
7
\(Perimeter = 120 + 120 + 30\pi + 30\pi = 240 + 60\pi\)

Refer the modified diagram below:

Attachment:
Untitled.png
Untitled.png [ 33.11 KiB | Viewed 14654 times ]


At 178 seconds, when Team A completed the race, last runner of Team B had 42-35 = 7 seconds to complete the race.

We require to find the distance covered in last 7 seconds

Distance covered in 42 seconds is \(240 + 60\pi\), so distance covered in 7 seconds

\(= \frac{7}{42} * (240 + 60\pi) = 40 + 10\pi\)

Answer = B
_________________

Kindly press "+1 Kudos" to appreciate :)

General Discussion
Senior Manager
Senior Manager
User avatar
Joined: 13 Jun 2013
Posts: 275
Premium Member
Re: The figure below represents a track with identical semi-circular ends  [#permalink]

Show Tags

New post 06 Oct 2014, 11:01
11
5
Bunuel wrote:

Tough and Tricky questions: Distance/Rate .



The figure below represents a track with identical semi-circular ends used for a 4-lap relay race involving two 4-person teams (where each team member runs one complete lap around the track). The table below shows the lap times for each runner on Team A and Team B. Assuming that each runner runs at a constant rate, Team A win the race by how many meters?
Image

A. 40 meters

B. \((40 + 10\pi)\) meters

C. \((40 + 20\pi)\) meters

D. \((20 + 10\pi)\) meters

E. \((20 + 20\pi)\) meters

Attachment:
Untitled.png


radius of the curved part (semi-circle) = 1/2(60) =30
thus perimeter of the track (120*2) + 2pi(30) = 240 + 60pi

now as per the chart, team A beats team b by 7 sec. obviously, the final lap is run by the last runner of team B which takes 42 seconds to run the complete track.

during these 7 secs, this last runner would have covered 7/42 = 1/6 of the lap.

thus Team A defeated team B by 1/6(240 + 60pi) = 40 + 10 pi

hence B
Intern
Intern
avatar
Joined: 12 Sep 2012
Posts: 25
GMAT 1: 550 Q49 V17
Re: The figure below represents a track with identical semi-circular ends  [#permalink]

Show Tags

New post 02 Dec 2014, 23:48
1
Hi,

I am unable to understand the solution of this question. Diameter of the semicircle is not given. However, diameter = 60 is being assumed by all solution providers. Kindly explain it in details. I will be grateful if anyone looks into this. :)
SVP
SVP
User avatar
Status: The Best Or Nothing
Joined: 27 Dec 2012
Posts: 1825
Location: India
Concentration: General Management, Technology
WE: Information Technology (Computer Software)
Re: The figure below represents a track with identical semi-circular ends  [#permalink]

Show Tags

New post 02 Dec 2014, 23:58
deya wrote:
Hi,

I am unable to understand the solution of this question. Diameter of the semicircle is not given. However, diameter = 60 is being assumed by all solution providers. Kindly explain it in details. I will be grateful if anyone looks into this. :)



Split the figure in 2 semicircles & 1 rectangle.

You get diameter = 60

It has been calculated; not assumed :)
_________________

Kindly press "+1 Kudos" to appreciate :)

Intern
Intern
avatar
B
Joined: 25 Dec 2016
Posts: 1
Re: The figure below represents a track with identical semi-circular ends  [#permalink]

Show Tags

New post 04 Jun 2017, 12:00
Why Distance covered in 42 seconds is 240+60π? I think It should be 1/4 of overall distance (240 + 60п)/4
Intern
Intern
avatar
B
Joined: 28 Apr 2016
Posts: 6
Re: The figure below represents a track with identical semi-circular ends  [#permalink]

Show Tags

New post 04 Jun 2017, 17:47
2
The answer has to be a factor of the perimeter i.e. 240+60pi.
Now 240+60pi = 6(40+10pi).
Only B satisfies this condition. No other calculation required.
DS Forum Moderator
avatar
P
Joined: 21 Aug 2013
Posts: 1412
Location: India
Premium Member
Re: The figure below represents a track with identical semi-circular ends  [#permalink]

Show Tags

New post 04 Jun 2017, 22:30
batyroff wrote:
Why Distance covered in 42 seconds is 240+60π? I think It should be 1/4 of overall distance (240 + 60п)/4


Hi

It is mentioned that its a 4-lap relay race.. which means every team member would run the entire lap (which is calculated already by many as 240+60п).

The table shows lap times for each runner, which means the times depicted are the times taken by each runner to run the complete lap, individually.

hope it helps.
Senior Manager
Senior Manager
avatar
G
Joined: 21 Aug 2016
Posts: 264
Location: India
GPA: 3.9
WE: Information Technology (Computer Software)
GMAT ToolKit User Reviews Badge CAT Tests
Re: The figure below represents a track with identical semi-circular ends  [#permalink]

Show Tags

New post 25 Jun 2017, 01:43
2
Can anyone please explain why the 4th member alone of team B is considered for running in delayed time?

By the question, I assumed/understood that all people of team B are running at the same time in competition with team A people. Then, why only 4th member race time is considered?
Manager
Manager
avatar
G
Joined: 09 Jun 2014
Posts: 219
Location: India
Concentration: General Management, Operations
Schools: Tuck '19
Premium Member Reviews Badge
Re: The figure below represents a track with identical semi-circular ends  [#permalink]

Show Tags

New post 07 Oct 2018, 20:17
ankitsood5 wrote:
The answer has to be a factor of the perimeter i.e. 240+60pi.
Now 240+60pi = 6(40+10pi).
Only B satisfies this condition. No other calculation required.



Please explain why it has to be a factor.
Intern
Intern
avatar
B
Joined: 13 Sep 2014
Posts: 1
Re: The figure below represents a track with identical semi-circular ends  [#permalink]

Show Tags

New post 13 Oct 2018, 20:37
1
Why is the distance to be covered in last 7 seconds found out by using 42 sec (time of team B player) and not by 41sec?
Manager
Manager
avatar
G
Joined: 09 Jun 2014
Posts: 219
Location: India
Concentration: General Management, Operations
Schools: Tuck '19
Premium Member Reviews Badge
Re: The figure below represents a track with identical semi-circular ends  [#permalink]

Show Tags

New post 13 Oct 2018, 21:06
smratikasharma wrote:
Why is the distance to be covered in last 7 seconds found out by using 42 sec (time of team B player) and not by 41sec?


Team A wins the race (That is after 178th second whatever distance is left will be the,distance left by Team B to cover the distance.So,this lag is from Team B which has to make up.



Press Kudos if it helps!!
Intern
Intern
avatar
B
Joined: 28 Aug 2018
Posts: 14
CAT Tests
Re: The figure below represents a track with identical semi-circular ends  [#permalink]

Show Tags

New post 12 Nov 2018, 06:17
I did it by a shortcut. So I know that the total distance for one round is (pi + 4) * 60. I just searched in the answer choices the ratio of the constant of pi and the constant in the parenthesis should be 1:4 respectively. Only B matches the answer.
GMAT Club Bot
Re: The figure below represents a track with identical semi-circular ends &nbs [#permalink] 12 Nov 2018, 06:17
Display posts from previous: Sort by

The figure below represents a track with identical semi-circular ends

  new topic post reply Question banks Downloads My Bookmarks Reviews Important topics  


Copyright

GMAT Club MBA Forum Home| About| Terms and Conditions and Privacy Policy| GMAT Club Rules| Contact| Sitemap

Powered by phpBB © phpBB Group | Emoji artwork provided by EmojiOne

Kindly note that the GMAT® test is a registered trademark of the Graduate Management Admission Council®, and this site has neither been reviewed nor endorsed by GMAC®.