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

It is currently 23 Oct 2019, 14:48

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

How long did it take Bob to complete the race?

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

Hide Tags

Find Similar Topics 
Math Expert
User avatar
V
Joined: 02 Sep 2009
Posts: 58464
How long did it take Bob to complete the race?  [#permalink]

Show Tags

New post 05 Mar 2019, 05:00
00:00
A
B
C
D
E

Difficulty:

  25% (medium)

Question Stats:

66% (01:03) correct 34% (01:28) wrong based on 109 sessions

HideShow timer Statistics

Intern
Intern
User avatar
B
Joined: 21 Apr 2014
Posts: 32
Re: How long did it take Bob to complete the race?  [#permalink]

Show Tags

New post 05 Mar 2019, 05:14
This is a "Value" DS question.

Value: The time it took Bob to finish.

Given information: We know that Distance = Rate x Time, so if we knew Distance/Rate, then we could find the Time. We could think of this question as asking, what is the ratio between Bob's Distance and Bob's Rate?

Need: Distance/Rate

Statement (1):

We know D = R x T.
This says that (5/3)D = R x 3.

Let's simplify:
(5/3)D = 3R
5D = 9R
D/R = 9/5

Sufficient! We found the ratio we were looking for!

Statement (2):

Average Speed = Total Distance / Total Time
30 = D/T

Unfortunately, we cannot find T. This is insufficient.

The answer is (A).
_________________
Vivian Kerr | GMAT/GRE Tutor @ http://www.gmatrockstar.com | gmatrockstar[at]gmail.com | solid 5-star reviews on Yelp!

Former Kaplan and Grockit instructor. I've freelanced with Veritas Prep, Magoosh, and most of the bigger test prep companies. Now offering Skype-based private tutoring for the GMAT and GRE.

Reading Comprehension is my jam! :)
GMAT Club Legend
GMAT Club Legend
User avatar
D
Joined: 18 Aug 2017
Posts: 5043
Location: India
Concentration: Sustainability, Marketing
GPA: 4
WE: Marketing (Energy and Utilities)
GMAT ToolKit User Premium Member
Re: How long did it take Bob to complete the race?  [#permalink]

Show Tags

New post 05 Mar 2019, 10:48
1
Bunuel wrote:
How long did it take Bob to complete the race?

(1) If Bob were 2/3 faster, his time would have been 3 hours.
(2) Bob’s average speed was 30 miles per hour.



let Bob intial speed = x
and distance =d
so
#1
d=s*t
intial speed =x and time taken (t)= D/x---(1)
now speed is 2x/3 faster
so distane is same but time = 3 hrs
so
we can say
3D/2x= 3
or D/x= 2
so substiuting in 1
we can say t = 2 hrs
sufficeint
#2
avg speed = total distance/total time
30 = D/T
values not know of D & T
in sufficeint
IMO A
Intern
Intern
avatar
B
Joined: 01 Jul 2018
Posts: 20
Re: How long did it take Bob to complete the race?  [#permalink]

Show Tags

New post 29 Apr 2019, 11:04
GMATRockstar wrote:
This is a "Value" DS question.

Value: The time it took Bob to finish.

Given information: We know that Distance = Rate x Time, so if we knew Distance/Rate, then we could find the Time. We could think of this question as asking, what is the ratio between Bob's Distance and Bob's Rate?

Need: Distance/Rate

Statement (1):

We know D = R x T.
This says that (5/3)D = R x 3.

Let's simplify:
(5/3)D = 3R
5D = 9R
D/R = 9/5

Sufficient! We found the ratio we were looking for!

Statement (2):

Average Speed = Total Distance / Total Time
30 = D/T

Unfortunately, we cannot find T. This is insufficient.

The answer is (A).


I am missing sth..

How do you set this up?
Statement (1):

We know D = R x T.
This says that (5/3)D = R x 3.

I thought 5/3 was the rate not the D...

thanks,
GMAT Club Bot
Re: How long did it take Bob to complete the race?   [#permalink] 29 Apr 2019, 11:04
Display posts from previous: Sort by

How long did it take Bob to complete the race?

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





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