Last visit was: 21 May 2024, 02:57 It is currently 21 May 2024, 02:57
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
SORT BY:
Date
Tags:
Show Tags
Hide Tags
Retired Moderator
Joined: 22 Jun 2014
Posts: 971
Own Kudos [?]: 3833 [29]
Given Kudos: 182
Location: India
Concentration: General Management, Technology
GMAT 1: 540 Q45 V20
GPA: 2.49
WE:Information Technology (Computer Software)
Send PM
Director
Director
Joined: 18 Jul 2018
Posts: 925
Own Kudos [?]: 1302 [4]
Given Kudos: 95
Location: India
Concentration: Operations, General Management
GMAT 1: 590 Q46 V25
GMAT 2: 690 Q49 V34
WE:Engineering (Energy and Utilities)
Send PM
Intern
Intern
Joined: 14 Feb 2018
Posts: 15
Own Kudos [?]: 2 [0]
Given Kudos: 22
Send PM
Director
Director
Joined: 18 Jul 2018
Posts: 925
Own Kudos [?]: 1302 [4]
Given Kudos: 95
Location: India
Concentration: Operations, General Management
GMAT 1: 590 Q46 V25
GMAT 2: 690 Q49 V34
WE:Engineering (Energy and Utilities)
Send PM
Re: Three automobiles travel distances that are in the ratios of 1:2:3. [#permalink]
3
Kudos
1
Bookmarks
justgottamakeit1592 wrote:
Afc0892 wrote:
Distance Ratio = 1x:2x:3x

Time taken ratio = 3x:2x:1x

Average speed = Total Distance/Time = 1/3 : 2/2 : 3/1
Taking LCM gives 1:3:9.

C is the answer.



Can you explain this a little further? How did you figure out you need to get the LCM? Also, how did you come up with the final ratio?


The ratio is 1/3 : 1 : 3/1
Since this option is not listed in the answer choices. We need to further simplify.
Now,
LCM of denominator is 3.
Now multiply the ratio by 3, we get

1/3*3 : 1*3 : 3/1*3
1:3:9

Hope it's clear

Posted from my mobile device
Intern
Intern
Joined: 14 Feb 2018
Posts: 15
Own Kudos [?]: 2 [0]
Given Kudos: 22
Send PM
Re: Three automobiles travel distances that are in the ratios of 1:2:3. [#permalink]
Ahh I see..thanks for the quick response!
Manager
Manager
Joined: 12 Apr 2011
Posts: 115
Own Kudos [?]: 200 [1]
Given Kudos: 86
Location: United Arab Emirates
Concentration: Strategy, Marketing
GMAT 1: 670 Q50 V31
GMAT 2: 720 Q50 V37
GPA: 3.2
WE:Marketing (Telecommunications)
Send PM
Re: Three automobiles travel distances that are in the ratios of 1:2:3. [#permalink]
1
Kudos
HKD1710 wrote:
Three automobiles travel distances that are in the ratios of 1:2:3. If the ratios of the traveling times over these distances for these automobiles are 3:2:1 in the same respective order, what are the ratios of their respective average speeds?

(A) 1:1:1
(B) 1:3:3
(C) 1:3:9
(D) 3:2:1
(E) 3:4:3

Project PS Butler : Question #51


Subscribe to get Daily Email - Click Here | Subscribe via RSS - RSS


Lets solve this problem by taking examples:

Distances are in the ratio --> 1:2:3
i.e.
Da = 100Kms
Db = 200Kms
Dc = 300Kms

Times are in the ratio --> 3:2:1
i.e.
Ta = 3 hours
Tb = 2 hours
Tc = 1 hour

Now:
Sa = 100kms/3 hours = 33.33 Kmph
Sb = 200kms/2 hours = 100 Kmph
Sc = 300kms/3 hours = 300kmph

Now Sa:Sb:Sc = 33.33:100:300 = 1:3:9

Hence C is the correct option
Target Test Prep Representative
Joined: 14 Oct 2015
Status:Founder & CEO
Affiliations: Target Test Prep
Posts: 18874
Own Kudos [?]: 22278 [1]
Given Kudos: 285
Location: United States (CA)
Send PM
Re: Three automobiles travel distances that are in the ratios of 1:2:3. [#permalink]
1
Kudos
Expert Reply
HKD1710 wrote:
Three automobiles travel distances that are in the ratios of 1:2:3. If the ratios of the traveling times over these distances for these automobiles are 3:2:1 in the same respective order, what are the ratios of their respective average speeds?

(A) 1:1:1
(B) 1:3:3
(C) 1:3:9
(D) 3:2:1
(E) 3:4:3


We can let the distance traveled by the three automobiles be 30, 60, and 90, and the traveling times be 3, 2 and 1, respectively. Thus, the average speeds are 30/3 = 10, 60/2 = 30, and 90/1 = 90, respectively. Therefore, the ratios of their respective average speeds are 10:30:90 or 1:3:9.

Answer: C
Current Student
Joined: 23 Apr 2018
Posts: 130
Own Kudos [?]: 63 [0]
Given Kudos: 176
Send PM
Re: Three automobiles travel distances that are in the ratios of 1:2:3. [#permalink]
justgottamakeit1592 wrote:
Afc0892 wrote:
Distance Ratio = 1x:2x:3x

Time taken ratio = 3x:2x:1x

Average speed = Total Distance/Time = 1/3 : 2/2 : 3/1
Taking LCM gives 1:3:9.

C is the answer.



Can you explain this a little further? How did you figure out you need to get the LCM? Also, how did you come up with the final ratio?



one may even ignore taking the LCM in this case, and just multiply each of the three ratios by 3, to make it a whole number ratio...

1/3*3 : 1*3 : 3*3
1 : 3 : 9 option (C)
User avatar
Non-Human User
Joined: 09 Sep 2013
Posts: 33131
Own Kudos [?]: 828 [0]
Given Kudos: 0
Send PM
Re: Three automobiles travel distances that are in the ratios of 1:2:3. [#permalink]
Hello from the GMAT Club BumpBot!

Thanks to another GMAT Club member, I have just discovered this valuable topic, yet it had no discussion for over a year. I am now bumping it up - doing my job. I think you may find it valuable (esp those replies with Kudos).

Want to see all other topics I dig out? Follow me (click follow button on profile). You will receive a summary of all topics I bump in your profile area as well as via email.
GMAT Club Bot
Re: Three automobiles travel distances that are in the ratios of 1:2:3. [#permalink]
Moderator:
Math Expert
93364 posts