Last visit was: 21 Apr 2026, 19:35 It is currently 21 Apr 2026, 19:35
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
User avatar
Bunuel
User avatar
Math Expert
Joined: 02 Sep 2009
Last visit: 21 Apr 2026
Posts: 109,728
Own Kudos:
Given Kudos: 105,800
Products:
Expert
Expert reply
Active GMAT Club Expert! Tag them with @ followed by their username for a faster response.
Posts: 109,728
Kudos: 810,477
 [28]
1
Kudos
Add Kudos
27
Bookmarks
Bookmark this Post
Most Helpful Reply
User avatar
chetan2u
User avatar
GMAT Expert
Joined: 02 Aug 2009
Last visit: 18 Apr 2026
Posts: 11,230
Own Kudos:
44,984
 [6]
Given Kudos: 335
Status:Math and DI Expert
Location: India
Concentration: Human Resources, General Management
GMAT Focus 1: 735 Q90 V89 DI81
Products:
Expert
Expert reply
GMAT Focus 1: 735 Q90 V89 DI81
Posts: 11,230
Kudos: 44,984
 [6]
4
Kudos
Add Kudos
2
Bookmarks
Bookmark this Post
General Discussion
avatar
allan89
Joined: 08 Sep 2013
Last visit: 17 Jul 2021
Posts: 15
Own Kudos:
10
 [3]
Given Kudos: 267
Posts: 15
Kudos: 10
 [3]
2
Kudos
Add Kudos
1
Bookmarks
Bookmark this Post
avatar
hassan6262
Joined: 09 May 2020
Last visit: 30 Jan 2024
Posts: 2
Given Kudos: 46
Posts: 2
Kudos: 0
Kudos
Add Kudos
Bookmarks
Bookmark this Post
can someone please explain this questio to me again? i am unable to understand
User avatar
ZNLove
Joined: 19 Jun 2018
Last visit: 16 Sep 2023
Posts: 38
Own Kudos:
Given Kudos: 89
Location: Brazil
GMAT 1: 650 Q44 V35
GPA: 3.5
WE:Analyst (Other)
Products:
GMAT 1: 650 Q44 V35
Posts: 38
Kudos: 9
Kudos
Add Kudos
Bookmarks
Bookmark this Post
hassan6262
can someone please explain this questio to me again? i am unable to understand
Same here. I found hard to understand the relation of the car and the bus!
User avatar
stne
Joined: 27 May 2012
Last visit: 21 Apr 2026
Posts: 1,808
Own Kudos:
Given Kudos: 678
Posts: 1,808
Kudos: 2,090
Kudos
Add Kudos
Bookmarks
Bookmark this Post
ZNLove
hassan6262
can someone please explain this questio to me again? i am unable to understand
Same here. I found hard to understand the relation of the car and the bus!


Hi ZNLove and hassan6262,
There was a small typo in the question, which has now been corrected. Hope the question will be easier to approach now.
User avatar
ScottTargetTestPrep
User avatar
Target Test Prep Representative
Joined: 14 Oct 2015
Last visit: 21 Apr 2026
Posts: 22,276
Own Kudos:
26,526
 [1]
Given Kudos: 302
Status:Founder & CEO
Affiliations: Target Test Prep
Location: United States (CA)
Expert
Expert reply
Active GMAT Club Expert! Tag them with @ followed by their username for a faster response.
Posts: 22,276
Kudos: 26,526
 [1]
1
Kudos
Add Kudos
Bookmarks
Bookmark this Post
Bunuel
A car is moving from A to B at a constant speed. After 80 km, due to an engine malfunction, the speed of the car decreases to 4/5th of the original speed. Because of that, the car reaches B 1 hour and 24 minutes later than intended. Had the same malfunction happened after the car travelled 120 km, the car would have reached B 1 hour later than intended. What was the original speed of the car?

A. 15 Km/hr
B. 20 Km/hr
C. 25 Km/hr
D. 30 Km/hr
E. 40 Km/hr

Let r = the original speed of the car and t = the regular time the car reaches its destination. We can create the equations:

rt = 80 + 4r/5 * (t + 1 + 24/60 - 80/r)

and

rt = 120 + 4r/5 * (t + 1 - 120/r)

Subtracting the second equation from the first, we have:

0 = -40 + 4r/5 * (24/60 + 40/r)

40 = 4r/5 * (2/5 + 40/r)

40 = 8r/25 + 32

8 = 8r/25

r = 8 * 25/8 = 25

Answer: C
avatar
kushtayal
Joined: 04 May 2020
Last visit: 31 May 2020
Posts: 3
Own Kudos:
Given Kudos: 17
Posts: 3
Kudos: 1
Kudos
Add Kudos
Bookmarks
Bookmark this Post
Can someone please post an easy to understand solution to the question!
@bunel, waiting to see your answer!
User avatar
SiddharthR
Joined: 22 Oct 2018
Last visit: 20 Feb 2022
Posts: 84
Own Kudos:
Given Kudos: 201
Location: United States (TX)
Concentration: Finance, Technology
GMAT 1: 590 Q42 V29
GMAT 2: 650 Q47 V33
GPA: 3.7
WE:Engineering (Consumer Electronics)
GMAT 2: 650 Q47 V33
Posts: 84
Kudos: 39
Kudos
Add Kudos
Bookmarks
Bookmark this Post
kushtayal
Can someone please post an easy to understand solution to the question!
@bunel, waiting to see your answer!


This question is easy when you practice various types of them. Lets jump into it

There are 3 scenarios : 1) When the vehicle has no Engine Malfunctions, 2) When Engine Malfunction occurs after 80 Kms, 3) When the Engine Malfunctions after 120 Kms

Let us take Scenario 1. When the engine doesn't malfunction, we can assume that the car travels a distance 'D' at a rate 'R' at time 'T'. We only have variables to work with so lets just keep it that way. We get D = RT (from the formula)

From Scenario 2, note that the distance traveled by the car at the end of the trip is same as above 'D', but the rate and the time it takes to reach the destination is different. Lets say that Scenario 2 has two trips [Trip 1 + Trip 2] [NOTE: Distance of Trip 1 + Distance of Trip 2 = D (When No Engine Malfunctions Occur]

For Trip 1, the car travels 80 Km with no engine malfunctions. In this case we get D = RT --> 80 = RT1
For Trip 2, the car travels the remaining distance (D - 80) at 4/5 the original rate. So we get D-80 = 4/5(R)T2

Note that we only have a relation between T & T1 & T2 from the question as follows -> T1 + T2 = T + 1hr 24 mins;

Now we can use the above equations to perform the following (Remember the criteria -- Distance traveled Is the same SAME regardless of when the malfunction occurred)

So we have D = 80 (Trip 1 Distance) + D-80 (Trip 2 Distance)

RT = 80 + 4/5(R)T2
RT = 80 + 4/5(R)[T + 1hr 24 mins - T1]
RT = 80 + 4/5(R)[T + 1hr 24 mins - 80/R] (The 80/R is the time from Trip 1 --> Refer to equation Trip 1) ---> 1

The same procedure is followed for Trip 2, we get the equation

RT = 120 + 4/5(R)[T + 1 - 120/R] --> 2

Subtracting 2 from 1, we can isolate variable R and end up with 25 Km/hr



Hope its clear now
User avatar
bumpbot
User avatar
Non-Human User
Joined: 09 Sep 2013
Last visit: 04 Jan 2021
Posts: 38,957
Own Kudos:
Posts: 38,957
Kudos: 1,117
Kudos
Add Kudos
Bookmarks
Bookmark this Post
Automated notice from GMAT Club BumpBot:

A member just gave Kudos to this thread, showing it’s still useful. I’ve bumped it to the top so more people can benefit. Feel free to add your own questions or solutions.

This post was generated automatically.
Moderators:
Math Expert
109728 posts
Tuck School Moderator
853 posts