GMAT Question of the Day: Daily via email | Daily via Instagram New to GMAT Club? Watch this Video

It is currently 06 Jul 2020, 13:47

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

Cathy traveled half of the journey by train at 80 kmph, half of the re

  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: 65014
Cathy traveled half of the journey by train at 80 kmph, half of the re  [#permalink]

Show Tags

New post 17 Apr 2020, 03:37
1
2
00:00
A
B
C
D
E

Difficulty:

  25% (medium)

Question Stats:

79% (02:02) correct 21% (02:01) wrong based on 57 sessions

HideShow timer Statistics

PS Forum Moderator
User avatar
G
Joined: 18 Jan 2020
Posts: 1035
Location: India
GPA: 4
CAT Tests
Re: Cathy traveled half of the journey by train at 80 kmph, half of the re  [#permalink]

Show Tags

New post 17 Apr 2020, 04:20
Let the total distance be X
Cathy travelled half of the distance at 80kmph by train
Then time taken throughout the train journey
(X/2)/80----(1) {distance/speed}
Cathy travelled half of the rest distance at 40kmph by bus
Then time taken throughout the bus journey
(X/4)/40---(2) {distance/speed}
Cathy travelled remaining distance by bicycle at 20kmph
Then time taken throughout the bicycle journey
(X/4)/20----(3)
{distance/speed}
Total time taken throughout journey=(1)+(2)+(3)
(X/2)/80+(X/4)/40+(X+4)/20
X/160+X/160+X/80
4X/160
Total time= X/40
Total distance=X
Average Speed= Total Distance/Total time
=X/(X/40)
Average Speed = 40

OA is B

Posted from my mobile device
GMATWhiz Representative
User avatar
G
Joined: 07 May 2019
Posts: 802
Location: India
Re: Cathy traveled half of the journey by train at 80 kmph, half of the re  [#permalink]

Show Tags

New post 17 Apr 2020, 04:23
Bunuel wrote:
Cathy traveled half of the journey by train at 80 kmph, half of the remaining journey by bus at 40 kmph and the remaining part of the journey by bicycle at 20 kmph. What was Cathy's average speed for the entire journey ?

A. 30 kmph
B. 40 kmph
C. 45 kmph
D. 50 kmph
E. 60 kmph



Solution:


Let x km be the total distance of Cathy’s journey.
    • Distance travelled by train = \(\frac{x}{2}\) km
      o Time taken to cover \(\frac{x}{2} = \frac{x}{160}\)
    • Distance travelled by bus = \(\frac{x}{4}\)
      o Time taken to cover \(\frac{x}{4} = \frac{x}{160}\)
    • Distance travelled by bicycle = \(\frac{x}{4}\)
      o Time taken to cover \(\frac{x}{4} = \frac{x}{80}\)
    • Total time taken = \(\frac{x}{160} + \frac{x}{160} +\frac{x}{80} =\frac{4x}{160} = \frac{x}{40}\)
    • Average speed = \(\frac{distance}{time}\) = \(\frac{x}{\frac{x}{40}} = 40\)kmph
Hence, the correct answer is Option B.
_________________

GMAT Prep truly Personalized using Technology

Prepare from an application driven course that serves real-time improvement modules along with a well-defined adaptive study plan. Start a free trial to experience it yourself and get access to 25 videos and 300 GMAT styled questions.

Helpful Links

Score Improvement Strategy: How to score Q50+ on GMAT | 5 steps to Improve your Verbal score
Study Plan Articles: 3 mistakes to avoid while preparing | How to create a study plan? | The Right Order of Learning | Importance of Error Log
Helpful Quant Strategies: Filling Spaces Method | Avoid Double Counting in P&C | The Art of Not Assuming anything in DS | Number Line Method
Key Verbal Techniques: Plan-Goal Framework in CR | Quantifiers the tiny Game-changers | Countable vs Uncountable Nouns | Tackling Confusing Words in Main Point
GMAT Club Legend
GMAT Club Legend
User avatar
V
Status: GMATINSIGHT Tutor
Joined: 08 Jul 2010
Posts: 4322
Location: India
GMAT: QUANT EXPERT
Schools: IIM (A)
GMAT 1: 750 Q51 V41
WE: Education (Education)
Reviews Badge
Re: Cathy traveled half of the journey by train at 80 kmph, half of the re  [#permalink]

Show Tags

New post 17 Apr 2020, 07:08
Bunuel wrote:
Cathy traveled half of the journey by train at 80 kmph, half of the remaining journey by bus at 40 kmph and the remaining part of the journey by bicycle at 20 kmph. What was Cathy's average speed for the entire journey ?

A. 30 kmph
B. 40 kmph
C. 45 kmph
D. 50 kmph
E. 60 kmph


CONCEPT: Average Speed = \(\frac{Total DIstance }{ Total Time}\)


DIstance = Speed* Time

Total Distance = D

Time of train Journey = (D/2)/80
Time of Bus Journey = (D/4)/40
Time of Cycle Journey = (D/4)/20

Total Time = (D/160) + (D/160) + (D/80) = (4D/160) = (D/40)

Average Speed = D/(D/40) = 40 kmph

Answer: Option B
_________________
Prepare with PERFECTION to claim Q≥50 and V≥40 !!!
GMATinsight .............(Bhoopendra Singh and Dr.Sushma Jha)
e-mail: info@GMATinsight.com l Call : +91-9999687183 / 9891333772
One-on-One Skype classes l Classroom Coaching l On-demand Quant course l Admissions Consulting

Most affordable l Comprehensive l 2000+ Qn ALL with Video explanations l LINK: Courses and Pricing
Click for FREE Demo on VERBAL & QUANT
Our SUCCESS STORIES: From 620 to 760 l Q-42 to Q-49 in 40 days l 590 to 710 + Wharton l
FREE GMAT Resource: 22 FREE (FULL LENGTH) GMAT CATs LINKS l NEW OG QUANT 50 Qn+VIDEO Sol.
Manager
Manager
User avatar
S
Joined: 21 Jan 2020
Posts: 66
Re: Cathy traveled half of the journey by train at 80 kmph, half of the re  [#permalink]

Show Tags

New post 17 Apr 2020, 07:28
Bunuel wrote:
Cathy traveled half of the journey by train at 80 kmph, half of the remaining journey by bus at 40 kmph and the remaining part of the journey by bicycle at 20 kmph. What was Cathy's average speed for the entire journey ?

A. 30 kmph
B. 40 kmph
C. 45 kmph
D. 50 kmph
E. 60 kmph


The answer is B

Let the distance be d .

Time to cover 1/2 the distance at 80 km/hr = d/160
Time to cover 1/4 the distance at 40 km/hr = d/160
Time to cover 1/4 the distance at 20 km/hr = d/80

Total Time : d/40

Therefore Average Speed = d/(d/40) =40 (B)
GMAT Club Legend
GMAT Club Legend
User avatar
V
Joined: 18 Aug 2017
Posts: 6427
Location: India
Concentration: Sustainability, Marketing
GPA: 4
WE: Marketing (Energy and Utilities)
GMAT ToolKit User Reviews Badge CAT Tests
Re: Cathy traveled half of the journey by train at 80 kmph, half of the re  [#permalink]

Show Tags

New post 17 Apr 2020, 07:31
Bunuel wrote:
Cathy traveled half of the journey by train at 80 kmph, half of the remaining journey by bus at 40 kmph and the remaining part of the journey by bicycle at 20 kmph. What was Cathy's average speed for the entire journey ?

A. 30 kmph
B. 40 kmph
C. 45 kmph
D. 50 kmph
E. 60 kmph


let total distance be x
so first half of distance ; x/2
2nd half of the remaining ; x/2 * 1/2 ; x/4
and balance distance ; x-(x/2+x/4) = x/4
so avg time would be ; total distance/total speed
x/2 * 1/80 + x/4 * 1/40 + x/4 * 1/20
=> 4x/160 ; x/40
avg speed of complete journey
x/x/40 ; 40 kmph
OPTION B :)
Director
Director
User avatar
D
Joined: 16 Jan 2019
Posts: 651
Location: India
Concentration: General Management
WE: Sales (Other)
Re: Cathy traveled half of the journey by train at 80 kmph, half of the re  [#permalink]

Show Tags

New post 17 Apr 2020, 07:42
Assume that the total distance is 800km

First 400km is covered in 400/80=5hours

Next 200km is covered in 200/40=5hours

Final 200km is covered in 200/20=10hours

Total time taken to cover 800km=5+5+10=20 hours

Average speed for entire journey =800/20=40kmph

Answer is (B)

Posted from my mobile device
Director
Director
User avatar
D
Joined: 12 Dec 2015
Posts: 525
Re: Cathy traveled half of the journey by train at 80 kmph, half of the re  [#permalink]

Show Tags

New post 17 Apr 2020, 08:47
Cathy traveled half of the journey by train at 80 kmph, half of the remaining journey by bus at 40 kmph and the remaining part of the journey by bicycle at 20 kmph. What was Cathy's average speed for the entire journey ?

A. 30 kmph
B. 40 kmph --> correct: let's say, total distance=4d, so Cathy's average speed = 4d/( (2d/80)+(d/40)+(d/20) ) = 4d/( (d/40)+(d/40)+(d/20) ) = 4d/( (2d/40)+(d/20) )= 4d/( (d/20)+(d/20) ) = 4d/(2d/20)=4d/(d/10)=40kmph
C. 45 kmph
D. 50 kmph
E. 60 kmph
GMAT Club Bot
Re: Cathy traveled half of the journey by train at 80 kmph, half of the re   [#permalink] 17 Apr 2020, 08:47

Cathy traveled half of the journey by train at 80 kmph, half of the re

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





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