Find all School-related info fast with the new School-Specific MBA Forum

It is currently 29 Aug 2014, 02:14

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.

Events & Promotions

Events & Promotions in June
Open Detailed Calendar

During a trip, Francine traveled x percent of the total

  Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
TAGS:
Manager
Manager
avatar
Joined: 08 Apr 2004
Posts: 137
Location: Corea
Followers: 1

Kudos [?]: 55 [0], given: 0

During a trip, Francine traveled x percent of the total [#permalink] New post 05 Sep 2004, 06:17
00:00
A
B
C
D
E

Difficulty:

(N/A)

Question Stats:

0% (00:00) correct 0% (00:00) wrong based on 0 sessions
During a trip, Francine traveled x percent of the total distance at an average speed of 40 miles per hour and the rest of the distance at an average speed of 60 miles per hour. In terms of x, what was Francine’s average speed for the entire trip?

180-x/2


x+60/2


300-x/5


600/115-x


1200/x+200
Director
Director
avatar
Joined: 20 Jul 2004
Posts: 593
Followers: 1

Kudos [?]: 21 [0], given: 0

GMAT Tests User
 [#permalink] New post 05 Sep 2004, 08:52
I got 12000/(x+200).
Could E be a typo missing a zero?
Manager
Manager
avatar
Joined: 18 Jun 2004
Posts: 105
Location: san jose , CA
Followers: 1

Kudos [?]: 14 [0], given: 0

GMAT Tests User
 [#permalink] New post 05 Sep 2004, 11:33
Hey guys can you explain your answers i am kind of lost .
_________________

---- Hero never chooses Destiny
Destiny chooses Him ......

Intern
Intern
avatar
Joined: 10 Aug 2004
Posts: 40
Followers: 0

Kudos [?]: 1 [0], given: 0

 [#permalink] New post 05 Sep 2004, 13:20
i am with hardworking on this one. I think the individual who posted forgot to include the final zero on answer E. I plugged in and said that the traveler drove 50%,x, of 120 miles trip at 40 mph and the other half at 60 mph. Therefore the total traveling time was 2.5 hours for 120 miles and the average speed was 48 mph. C comes close but if you add another zero to E, then 250x48=12,000.
Manager
Manager
avatar
Joined: 05 Sep 2004
Posts: 97
Followers: 1

Kudos [?]: 3 [0], given: 0

 [#permalink] New post 05 Sep 2004, 15:09
Actually, none of the answers is correct.

The correct answer is 120/(x + 2).

Here's the derivation:

Suppose total distance travelled is 1 mile. Then, x and (1-x) become actuall distances travelled and not just percentages.

Total distance travelled = S = x + 1 - x = 1

Total time taken = t = (x/40 mph) + [(1-x)/60 mph] = (3x + 2 - 2x) / 120 = (x+2)/120

Average speed = S / t = 1 / [(x+2)/120] = 120/(x+2)

The other suggested answer: 12000/(x+200) will not work, as x is in percentages/proportions and not actual units.
Director
Director
avatar
Joined: 20 Jul 2004
Posts: 593
Followers: 1

Kudos [?]: 21 [0], given: 0

GMAT Tests User
 [#permalink] New post 06 Sep 2004, 08:31
I stay corrected at 12000/(x+200).

My explanation:
Let the total distance traveled be A.
First Section: Distance = xA/100, Speed = 40, Time = xA/4000
Second Section: Distance = A(100-x)/100, Speed = 60, Time = A(100-x)/6000

Total journey: Distance = A, Time = [xA/4000+ A(100-x)/6000]
Ave. Speed = [A] / [xA/4000+ A(100-x)/6000]
= 12000/(x+200).

Recheck:
For checking back, lets say he travelled a total distance of (A=) 60 miles, and x = 25%
First Section: Distance = 15, Speed = 40, Time = 15/40
Second Section: Distance = 45, Speed = 60, Time = 45/60
Total journey: Distance = 60, Time = 135/120, Ave. Speed = 160/3
Substitute x=25 in 12000/(x+200), you get 160/3

PS:
I had initially taken total distance to be 100 for simplicity in calculation. But took a generic distance of A, just to prove the point.
Manager
Manager
avatar
Joined: 05 Sep 2004
Posts: 97
Followers: 1

Kudos [?]: 3 [0], given: 0

 [#permalink] New post 06 Sep 2004, 09:15
Well, you're assuming x to be in 100 percentage points. Although that's not what the question said, as long as you're explicitly saying that x is in 100 percentage point, your formula will be correct.

You can get my formula from yours by noticing that x is in 100 percentage points in your formula and dividing the numerator and denominator by 100. My formula is in percent/proportions. That's the only difference.
Manager
Manager
avatar
Joined: 08 Apr 2004
Posts: 137
Location: Corea
Followers: 1

Kudos [?]: 55 [0], given: 0

 [#permalink] New post 06 Sep 2004, 15:40
abennett wrote:
i am with hardworking on this one. I think the individual who posted forgot to include the final zero on answer E. I plugged in and said that the traveler drove 50%,x, of 120 miles trip at 40 mph and the other half at 60 mph. Therefore the total traveling time was 2.5 hours for 120 miles and the average speed was 48 mph. C comes close but if you add another zero to E, then 250x48=12,000.



OOPS!, my mistake , yes it is 12000 and the answer is E infact (1200/x+200)
  [#permalink] 06 Sep 2004, 15:40
    Similar topics Author Replies Last post
Similar
Topics:
4 Experts publish their posts in the topic During a trip, Francine traveled x percent of the total dist MBAhereIcome 6 26 Aug 2011, 12:28
31 Experts publish their posts in the topic During a trip, Francine traveled x percent of the total vksunder 27 02 Mar 2009, 16:27
1 Experts publish their posts in the topic During a trip, Francine traveled x percent of the total M8 3 30 Apr 2006, 07:23
During a trip on an expressway, Don drove a total of x jlui4477 3 20 Apr 2006, 19:54
during a trip on an expressway, Don drove a total of x ludwigvb 3 27 Jan 2006, 16:35
Display posts from previous: Sort by

During a trip, Francine traveled x percent of the total

  Question banks Downloads My Bookmarks Reviews Important topics  


cron

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

Powered by phpBB © phpBB Group and phpBB SEO

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®.