It is currently 24 Nov 2017, 01:03

### 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

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

# Events & Promotions

###### Events & Promotions in June
Open Detailed Calendar

# Lexy walks 5 miles from point A to point B in one hour, then

Author Message
TAGS:

### Hide Tags

Intern
Joined: 26 Jun 2012
Posts: 24

Kudos [?]: 139 [0], given: 1

Location: Germany
GMAT 1: 570 Q31 V39
GMAT 2: 710 Q43 V44
Lexy walks 5 miles from point A to point B in one hour, then [#permalink]

### Show Tags

21 Jul 2013, 14:16
7
This post was
BOOKMARKED
00:00

Difficulty:

55% (hard)

Question Stats:

68% (01:19) correct 32% (01:12) wrong based on 517 sessions

### HideShow timer Statistics

Lexy walks 5 miles from point A to point B in one hour, then bicycles back to point A along the same route at 15 miles per hour. Ben makes the same round trip, but does so at half of Lexy’s average speed. How many minutes does Ben spend on his round trip?

A. 40
B. 80
C. 120
D. 160
E. 180
[Reveal] Spoiler: OA

Kudos [?]: 139 [0], given: 1

Math Expert
Joined: 02 Sep 2009
Posts: 42355

Kudos [?]: 133182 [2], given: 12439

Re: Lexy walks 5 miles from point A to point B in one hour, then [#permalink]

### Show Tags

21 Jul 2013, 14:24
2
KUDOS
Expert's post
6
This post was
BOOKMARKED
kingflo wrote:
Lexy walks 5 miles from point A to point B in one hour, then bicycles back to point A along the same route at 15 miles per hour. Ben makes the same round trip, but does so at half of Lexy’s average speed. How many minutes does Ben spend on his round trip?

A. 40
B. 80
C. 120
D. 160
E. 180

$$average \ speed=\frac{total \ distance}{total \ time}=\frac{5+5}{1+\frac{5}{15}}=\frac{15}{2}$$ miles per hour.

Ben's average speed = $$\frac{15}{4}$$ miles per hour (half of Lexy's).

Ben's time = $$\frac{distance}{speed}=\frac{10}{(\frac{15}{4})}=\frac{8}{3}$$ hours, or 8/3*60=160 minutes.

_________________

Kudos [?]: 133182 [2], given: 12439

Senior Manager
Joined: 13 May 2013
Posts: 459

Kudos [?]: 202 [0], given: 134

Re: Lexy walks 5 miles from point A to point B in one hour, then [#permalink]

### Show Tags

02 Aug 2013, 12:16
Lexy walks 5 miles from point A to point B in one hour, then bicycles back to point A along the same route at 15 miles per hour. Ben makes the same round trip, but does so at half of Lexy’s average speed. How many minutes does Ben spend on his round trip?

Average speed = total distance/total time

We know the total distance is 5+5 (going from A to B then from B to A)

Time = distance/speed
Time = 5/15
Time = 1/3 hour

Average speed = (10)/(1hr + 1/3hr)
Average speed (lexi) = 10 / 1.33
Therefore, if Ben's average speed is 1/2 of lexi's then his speed = 10/2.66.

This means it took him 2.66 hours to cover the same 10 miles Lexi did. 2.66 hours = roughly 160 minutes.

Kudos [?]: 202 [0], given: 134

SVP
Status: The Best Or Nothing
Joined: 27 Dec 2012
Posts: 1851

Kudos [?]: 2723 [1], given: 193

Location: India
Concentration: General Management, Technology
WE: Information Technology (Computer Software)
Re: Lexy walks 5 miles from point A to point B in one hour, then [#permalink]

### Show Tags

29 Oct 2013, 20:20
1
KUDOS
Lexy travels 10 miles (5+5) in 80 Mins (60 + 60/3)
So, speed of Lexy = 10/80 = 1/8

Speed of Ben is half of speed of Lexy = 1/16

So, time taken by Ben = 10 / (1/16) = 160 Minutes

_________________

Kindly press "+1 Kudos" to appreciate

Kudos [?]: 2723 [1], given: 193

Director
Affiliations: CrackVerbal
Joined: 03 Oct 2013
Posts: 512

Kudos [?]: 595 [4], given: 6

Location: India
GMAT 1: 780 Q51 V46
Re: Lexy walks 5 miles from point A to point B in one hour, then [#permalink]

### Show Tags

29 Oct 2013, 22:29
4
KUDOS
kingflo wrote:
Lexy walks 5 miles from point A to point B in one hour, then bicycles back to point A along the same route at 15 miles per hour. Ben makes the same round trip, but does so at half of Lexy’s average speed. How many minutes does Ben spend on his round trip?

A. 40
B. 80
C. 120
D. 160
E. 180

Time taken by Lexy: 1 hour + 5/15 = 1 + 1/3 hours i.e 1 hour and 20 minutes

If Ben travels at half the speed then the time taken will be doubled: 2 hours and 40 minutes which is 120 + 40 = 160 minutes

Pushpinder Gill
Quantitative Instructor
_________________

Enroll for our GMAT Trial Course here -
http://gmatonline.crackverbal.com/

Learn all PS and DS strategies here-
http://gmatonline.crackverbal.com/p/mastering-quant-on-gmat

Kudos [?]: 595 [4], given: 6

Director
Joined: 23 Jan 2013
Posts: 603

Kudos [?]: 27 [0], given: 41

Schools: Cambridge'16
Lexy walks 5 miles from point A to point B in one hour, then [#permalink]

### Show Tags

09 Aug 2015, 08:32
Harmonic average for average speed: 2/(1/5+1/15)=15/2

the half speed: 15/2:2=15/4

10/(15/4)=8/3h*60=160min.

D

Kudos [?]: 27 [0], given: 41

Senior Manager
Joined: 28 Jun 2015
Posts: 300

Kudos [?]: 109 [0], given: 47

Concentration: Finance
GPA: 3.5
Re: Lexy walks 5 miles from point A to point B in one hour, then [#permalink]

### Show Tags

09 Aug 2015, 09:02
Time taken by Lexy to walk from point B to A => 60*5/15 = 20 mins.

Average speed of Lexy = 5+5/(60+20) = 10/80 = 7.5 mph.

Ben's average speed = 7.5/2 = 3.75 mph.

Time taken by Ben = 10*60/3.75 = 160 mins. Ans (D).
_________________

I used to think the brain was the most important organ. Then I thought, look what’s telling me that.

Kudos [?]: 109 [0], given: 47

Intern
Joined: 28 Sep 2014
Posts: 19

Kudos [?]: 13 [0], given: 88

D: M
GMAT 1: 700 Q49 V35
WE: Information Technology (Consulting)
Re: Lexy walks 5 miles from point A to point B in one hour, then [#permalink]

### Show Tags

03 Dec 2016, 01:59
Total time taken by Ben will be twice the total time taken by Lexy
ie from 2 * ( 1+15/5) = 2* ( 4/3) = 8/3 hours = 8*60/3 minutes = 160 minutes

Kudos [?]: 13 [0], given: 88

Manager
Joined: 19 Aug 2016
Posts: 60

Kudos [?]: 3 [0], given: 1

Re: Lexy walks 5 miles from point A to point B in one hour, then [#permalink]

### Show Tags

27 Oct 2017, 23:28
Bunuel wrote:
kingflo wrote:
Lexy walks 5 miles from point A to point B in one hour, then bicycles back to point A along the same route at 15 miles per hour. Ben makes the same round trip, but does so at half of Lexy’s average speed. How many minutes does Ben spend on his round trip?

A. 40
B. 80
C. 120
D. 160
E. 180

$$average \ speed=\frac{total \ distance}{total \ time}=\frac{5+5}{1+\frac{5}{15}}=\frac{15}{2}$$ miles per hour.

Ben's average speed = $$\frac{15}{4}$$ miles per hour (half of Lexy's).

Ben's time = $$\frac{distance}{speed}=\frac{10}{(\frac{15}{4})}=\frac{8}{3}$$ hours, or 8/3*60=160 minutes.

Hi Bunuel,

Can u tell me why we can't use this formula?

Avg speed=2ab/a+b

Kudos [?]: 3 [0], given: 1

Manager
Joined: 19 Aug 2016
Posts: 60

Kudos [?]: 3 [0], given: 1

Re: Lexy walks 5 miles from point A to point B in one hour, then [#permalink]

### Show Tags

27 Oct 2017, 23:39
kingflo wrote:
Lexy walks 5 miles from point A to point B in one hour, then bicycles back to point A along the same route at 15 miles per hour. Ben makes the same round trip, but does so at half of Lexy’s average speed. How many minutes does Ben spend on his round trip?

A. 40
B. 80
C. 120
D. 160
E. 180

1/2 of Lexy's average speed is Ben's speed..

1/2(2ab/a+b)
=1/2*{(2*15*5)/15+5)}
=3.75..

We need the time in minutes so Total dis/Total time=Average speed

10/x=3.75/60
Therefore, x=160 minutes

Kudos [?]: 3 [0], given: 1

Intern
Joined: 04 May 2015
Posts: 15

Kudos [?]: 5 [0], given: 13

Re: Lexy walks 5 miles from point A to point B in one hour, then [#permalink]

### Show Tags

28 Oct 2017, 08:40
kingflo wrote:
Lexy walks 5 miles from point A to point B in one hour, then bicycles back to point A along the same route at 15 miles per hour. Ben makes the same round trip, but does so at half of Lexy’s average speed. How many minutes does Ben spend on his round trip?

A. 40
B. 80
C. 120
D. 160
E. 180

Lexy Avg speed: (5+5)/(1+1/3)=7.5
ben's speed : 7.5/2
time taken by ben: (10*2/7.5)*60=160 mins

Kudos [?]: 5 [0], given: 13

Intern
Joined: 04 May 2015
Posts: 15

Kudos [?]: 5 [0], given: 13

Re: Lexy walks 5 miles from point A to point B in one hour, then [#permalink]

### Show Tags

28 Oct 2017, 08:41
kingflo wrote:
Lexy walks 5 miles from point A to point B in one hour, then bicycles back to point A along the same route at 15 miles per hour. Ben makes the same round trip, but does so at half of Lexy’s average speed. How many minutes does Ben spend on his round trip?

A. 40
B. 80
C. 120
D. 160
E. 180

Lexy Avg speed: (5+5)/(1+1/3)=7.5
ben's speed : 7.5/2
time taken by ben: (10*2/7.5)*60=160 mins

Kudos [?]: 5 [0], given: 13

Re: Lexy walks 5 miles from point A to point B in one hour, then   [#permalink] 28 Oct 2017, 08:41
Display posts from previous: Sort by