(Go: >> BACK << -|- >> HOME <<)
Last visit was: 21 May 2024, 03:39 It is currently 21 May 2024, 03:39
Decision Tracker
My Rewards
Unanswered
Active Topics
New posts
New comers' posts
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.
Go to My Error Log Learn more
Close
Request Expert Reply
Confirm Cancel

A man covered a certain distance at some

SORT BY:
Date
Kudos
Tags:
Find Similar Topics 
Show Tags
Hide Tags
User avatar
G
dharam44
Manager
Manager
Joined: 03 Nov 2018
Posts: 73
Own Kudos [?]: 85 [12]
Given Kudos: 209
Location: India
Schools: LBS '21
GMAT 1: 580 Q44 V28
GPA: 3.44
Send PM
A man covered a certain distance at some [#permalink] A man covered a certain distance at some   03 Nov 2018, 23:14
2
Kudos
10
Bookmarks
00:00
A
B
C
D
E

Difficulty:

65% (hard)

Question Stats:

64% (03:24) correct 36% (02:48) wrong based on 99 sessions
Hide Show timer Statistics
A man covered a certain distance at some speed. Had he moved 3 kmph faster, he would have taken 40 minutes less. If he had moved 2 kmph slower, he would have taken 40 minutes more. The distance (in km) is:

A. 35
B. 36
C. 37
D. 40
E. 25­
ShowHide Answer
Official Answer
D
Most Helpful Reply
User avatar
L
GMATinsight
GMAT Club Legend
GMAT Club Legend
Joined: 08 Jul 2010
Status:GMAT/GRE Tutor l Admission Consultant l On-Demand Course creator
Posts: 5985
Own Kudos [?]: 13498 [7]
Given Kudos: 124
Location: India
GMAT: QUANT+DI EXPERT
Schools: IIM (A) ISB '24
GMAT 1: 750 Q51 V41
WE:Education (Education)
Send PM
Reviews Badge
Re: A man covered a certain distance at some [#permalink] A man covered a certain distance at some   04 Nov 2018, 00:35
5
Kudos
2
Bookmarks
Expert Reply
dharam44 wrote:
A man covered a certain distance at some speed. Had he moved 3 kmph faster, he would have taken 40 minutes less. If he had moved 2 kmph slower, he would have taken 40 minutes more. The distance (in km) is:
A.35
B.36
C.37
D.40
E. 25


Let, Original speed = s
Distance = d
Time = t mins

Here we get three equations as per the given information

d = s*t

d = (s+3)*(t-40)

d = (s-2)*(t+40)


Solving equation 1 and 2

s*t = (s+3)*(t-40)
i.e. s*t = s*t +3t-40s-120

i.e. 3t-40s = 120

Solving equation 1 and 3

s*t = (s-2)*(t+40)
i.e. s*t = s*t -2t+40s-80

i.e. -2t+40s = 80

Solving the two blue and bold equations

t = 200 minutes
and s = 12 m/h

i.e. d = 12*(200/60) = 40 miles

Answer: Option D
General Discussion
User avatar
G
pandeyashwin
Manager
Manager
Joined: 14 Jun 2018
Posts: 171
Own Kudos [?]: 259 [0]
Given Kudos: 176
Send PM
Re: A man covered a certain distance at some [#permalink] A man covered a certain distance at some   04 Nov 2018, 01:34
\(\frac{d}{s} = t\) ; \(d = s*t\)

Given ,
\(d = (s-2)(t+\frac{2}{3})\) ------------------- 1

and ,

\(d = (s+3)(t-\frac{2}{3})\) -------------------- 2

Adding 1 & 2 ,

\(2d = (s-2)(t+\frac{2}{3})+(s+3)(t-\frac{2}{3})\)

\(2d = st + \frac{2}{3}s - 2t - \frac{4}{3} + st - \frac{2}{3}s +3t - 2\)

t = 3 hr 20 mins or 200 mins or \(\frac{10}{3}\)

If time is increased by 40 mins or \(\frac{40}{200}*100 = 20\)% , speed should be reduced by 16.67% or 1/6

\(\frac{5}{6}s = s - 2\)
s = 12 km/hr

\(d = \frac{10}{3} * 10\) = 40km
User avatar
P
Bismarck
Manager
Manager
Joined: 18 Jun 2018
Posts: 222
Own Kudos [?]: 416 [0]
Given Kudos: 35
Send PM
Re: A man covered a certain distance at some [#permalink] A man covered a certain distance at some   16 Nov 2018, 06:25
dharam44 wrote:
A man covered a certain distance at some speed. Had he moved 3 kmph faster, he would have taken 40 minutes less. If he had moved 2 kmph slower, he would have taken 40 minutes more. The distance (in km) is:
A.35
B.36
C.37
D.40
E. 25


OA:D

Let the initial speed of man be \(x\) Kmph
Let the initial time taken by man be \(t\) hours

\(xt=(x+3)(t-\frac{40}{60})\)

\(-\frac{2}{3}x+3t=2\) .....(1)

\(xt=(x-2)(t+\frac{40}{60})\)

\(\frac{2}{3}x-2t=\frac{4}{3}\) .....(2)

Adding \((1)\) and \((2)\), we get

\(t=2+\frac{4}{3}=\frac{10}{3}\) hours

Putting \(t =\frac{10}{3}\)hours into \((1)\), we get

\(-\frac{2}{3}x+3*\frac{10}{3}=2\)

\(x=\frac{2-3*\frac{10}{3}}{-\frac{2}{3}}=\frac{-8}{-\frac{2}{3}}=12\) Kmph

Distance travelled \(= xt = 12*\frac{10}{3}= 40\) Kms
User avatar
bumpbot
Non-Human User
Joined: 09 Sep 2013
Posts: 33131
Own Kudos [?]: 828 [0]
Given Kudos: 0
Send PM
Re: A man covered a certain distance at some [#permalink] A man covered a certain distance at some   03 May 2024, 12:27
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.
gmatclubot
Re: A man covered a certain distance at some [#permalink]
03 May 2024, 12:27
Moderator:
Bunuel
Math Expert
93365 posts