Last visit was: 18 May 2026, 19:52 It is currently 18 May 2026, 19:52
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
655-705 (Hard)|   Math Related|               
User avatar
NitinPant
Joined: 15 Dec 2024
Last visit: 13 Apr 2026
Posts: 1
Given Kudos: 4
Posts: 1
Kudos: 0
Kudos
Add Kudos
Bookmarks
Bookmark this Post
User avatar
consistentprep
Joined: 31 Aug 2017
Last visit: 20 Mar 2026
Posts: 28
Own Kudos:
Given Kudos: 278
Posts: 28
Kudos: 46
Kudos
Add Kudos
Bookmarks
Bookmark this Post
User avatar
Rashad95
Joined: 03 Jul 2025
Last visit: 26 Sep 2025
Posts: 1
Own Kudos:
Location: Azerbaijan
GRE 1: Q162 V139
GPA: 94
WE:Project Management (Energy)
Kudos
Add Kudos
Bookmarks
Bookmark this Post
User avatar
siddharth_
Joined: 17 Oct 2023
Last visit: 18 May 2026
Posts: 81
Own Kudos:
Given Kudos: 149
Location: India
GMAT Focus 1: 675 Q85 V85 DI80
GPA: 8.6
Products:
GMAT Focus 1: 675 Q85 V85 DI80
Posts: 81
Kudos: 27
Kudos
Add Kudos
Bookmarks
Bookmark this Post
This approach is incorrect, and it cost me some time to figure out why, sharing here for anyone who gets confused like me.
At the end, v0+9d has been replaced with v10 but it should actually be v9. Why --


The approach starts with this -
v0 + (v0+d) + (v0+2d)+.........+(v0+8d)+(v0+9d) = 10/2[2v0 + (10-1)d]=10/2[2v0 + 9d]

and here the terms are v0, v1, v2.....v9 -- 10 terms total -- 10 segments of distances travelled.
fameatop
this question is a application of AP. and yes the previous answers are correct.

Speed at time '0' = v0
Speed at time '10' = v10
Lets assume the speed is increasing at a rate of 'd' m/s
Note:- Distance traveled in any 1 second is equal to the speed during that second.
Distance traveled in 1st sec = v0
Distance traveled in 2nd sec = v0+d
Distance traveled in 3rd sec = v0+2d
Distance traveled in 10th sec = v0+9d

So Total Distance traveled in 10 second can be given by
v0 + (v0+d) + (v0+2d)+.........+(v0+8d)+(v0+9d) = 10/2[2v0 + (10-1)d]=10/2[2v0 + 9d]

& as per question the bumper has traveled 125 m at the end of 10th second. So
10/2[2v0 + 9d]= 125
[2v0 + 9d]= 25
v0 + (v0+9d) = 25
v0 + v10 = 25......(1)

We are asked the value for speed at 0th & 10th second. From equation (1) we can say that the sum of speed at these moments is equal to 25.
The only options available are 5 , 20.

The speed v0 must be 5 & v10 must 20 because the speed is increasing at constant rate.
Note:- If the speed was decreasing at a constant rate, then v0=20 & v10=5

Hope it helps.
User avatar
egmat
User avatar
e-GMAT Representative
Joined: 02 Nov 2011
Last visit: 17 May 2026
Posts: 5,631
Own Kudos:
Given Kudos: 707
GMAT Date: 08-19-2020
Expert
Expert reply
Posts: 5,631
Kudos: 33,459
Kudos
Add Kudos
Bookmarks
Bookmark this Post
When the question says speed is increasing at a constant rate with respect to time, it means the amount of speed added per second is the same.

Think of it this way:
- Second 1: speed increases by 1.5 m/s
- Second 2: speed increases by 1.5 m/s
- Second 3: speed increases by 1.5 m/s
- ... and so on

This is linear growth (arithmetic): v = v0 + (constant × time)

What you're thinking of:
If V1/V0 = V2/V1 (constant ratio), that would be exponential growth - where speed multiplies by the same factor each second.

Why exponential doesn't match "constant rate":

Let's test: If v0 = 5 and speed multiplies by 1.15 each second:
- After 1 sec: 5 × 1.15 = 5.75 (increase of 0.75)
- After 2 sec: 5.75 × 1.15 = 6.61 (increase of 0.86)
- After 3 sec: 6.61 × 1.15 = 7.60 (increase of 0.99)

Notice: the increase keeps getting larger each second (0.750.860.99). That's NOT a constant rate - the rate itself is growing!

The correct interpretation:
"Constant rate of increase" = same amount added each second = linear/arithmetic growth

This is why we use: v10 = v0 + (acceleration × 10)

And for distance with constant acceleration:
Distance = Average Speed × Time = (v0 + v10)/2 × 10 = 125

This gives us: v0 + v10 = 25

Answer: v0 = 5, v10 = 20
heeeya
Thanks for the helpful adive.
But I wonder why the speed at 2nd sec is V0+d not V0 x r when it is said to increase at a 'rate'.
Doesn't it meant that V1/V0 = V2/V1?

User avatar
Flyingdutch1307
Joined: 10 Jul 2024
Last visit: 18 May 2026
Posts: 8
Own Kudos:
Given Kudos: 53
Posts: 8
Kudos: 1
Kudos
Add Kudos
Bookmarks
Bookmark this Post
I see a lot of detailed / complex explanation, Here is a simple breakdown

Speed - > increases constantly by some value "d"

therefore, Total Distance = t0*v0 + t1*v1....... + t10*v10 =S10

Since time increases by 1 sec, and speed is constantly increases, it forms an AP.

v1 = v0 + k
v2 = v1 + k = v0 + (2-1)k
... vn = vo + (n-1)k

total d = 125 = S10
Apply AP Sum formula

10/2 * (v0 + v10) = 125

v0 + v10 = 25 --- only possible values are 5, 20
User avatar
egmat
User avatar
e-GMAT Representative
Joined: 02 Nov 2011
Last visit: 17 May 2026
Posts: 5,631
Own Kudos:
Given Kudos: 707
GMAT Date: 08-19-2020
Expert
Expert reply
Posts: 5,631
Kudos: 33,459
Kudos
Add Kudos
Bookmarks
Bookmark this Post
Hi heeeya,

Great question! This is a very common and important distinction in math and physics.

The phrase 'speed is increasing at a constant rate with respect to time' means the speed increases by the SAME AMOUNT every second. This is an additive (linear) relationship, not a multiplicative (geometric) one.

Think of it this way:
- 'Constant rate of change' = the derivative is constant = the change per second is the same.
- So if speed increases by d meters per second every second: v(1) = v0 + d, v(2) = v0 + 2d, v(3) = v0 + 3d, etc.

What you're describing — V1/V0 = V2/V1 — would be a constant RATIO of change, which is geometric/exponential growth. The problem would need to say something like 'speed increases by a constant percentage each second' or 'speed doubles every second' for that interpretation.

In physics, 'increasing at a constant rate with respect to time' is simply constant acceleration. And with constant acceleration, we can use the formula:

Distance = Average Speed × Time
Distance = ((v0 + v10) / 2) × 10

Plugging in the given distance of [b]125 meters:[/b]
125 = ((v0 + v10) / 2) × 10
125 = 5 × (v0 + v10)
v0 + v10 = 25

Now we just need two choices that add to 25. Looking at our options: 5 + 20 = 25. That gives us v0 = 5 (Row 1 for v0) and v10 = 20 (Row 3 for v10).

Quick rule of thumb for the GMAT: 'constant rate' = additive/linear. 'Constant ratio' or 'constant percent' = multiplicative/geometric.

Answer: 1A, 3B
User avatar
Adit_
Joined: 04 Jun 2024
Last visit: 16 May 2026
Posts: 817
Own Kudos:
Given Kudos: 136
Products:
Posts: 817
Kudos: 269
Kudos
Add Kudos
Bookmarks
Bookmark this Post
This is typical sum of series formula applied:
n/2[a+l] = 125
[a+l] = 125/(10/2) = 25
Find a,l where a+l = 25.
Answer: 5,20

__________________

Edit: Not really sure why many are applying equations of motion here. GMAT doesn't need one to know them.
imhimanshu
A car is traveling on a straight stretch of roadway, and the speed of the car is increasing at a constant rate with respect to time. At time 0 seconds, the speed of the car is \(v_0\) meters per second; 10 seconds later, the front bumper of the car has traveled 125 meters, and the speed of the car is \(v_{10}\) meters per second.

Select values of \(v_0\) and \(v_{10}\) that are together consistent with the information provided. Make only two selections, one in each column.­

ID: 100401
User avatar
khalid03
Joined: 02 Nov 2023
Last visit: 17 May 2026
Posts: 6
Given Kudos: 330
Posts: 6
Kudos: 0
Kudos
Add Kudos
Bookmarks
Bookmark this Post
How do we get the 10/2 in the sum speed?

fameatop
this question is a application of AP. and yes the previous answers are correct.

Speed at time '0' = v0
Speed at time '10' = v10
Lets assume the speed is increasing at a rate of 'd' m/s
Note:- Distance traveled in any 1 second is equal to the speed during that second.
Distance traveled in 1st sec = v0
Distance traveled in 2nd sec = v0+d
Distance traveled in 3rd sec = v0+2d
Distance traveled in 10th sec = v0+9d

So Total Distance traveled in 10 second can be given by
v0 + (v0+d) + (v0+2d)+.........+(v0+8d)+(v0+9d) = 10/2[2v0 + (10-1)d]=10/2[2v0 + 9d]

& as per question the bumper has traveled 125 m at the end of 10th second. So
10/2[2v0 + 9d]= 125
[2v0 + 9d]= 25
v0 + (v0+9d) = 25
v0 + v10 = 25......(1)

We are asked the value for speed at 0th & 10th second. From equation (1) we can say that the sum of speed at these moments is equal to 25.
The only options available are 5 , 20.

The speed v0 must be 5 & v10 must 20 because the speed is increasing at constant rate.
Note:- If the speed was decreasing at a constant rate, then v0=20 & v10=5

Hope it helps.
User avatar
Adit_
Joined: 04 Jun 2024
Last visit: 16 May 2026
Posts: 817
Own Kudos:
Given Kudos: 136
Products:
Posts: 817
Kudos: 269
Kudos
Add Kudos
Bookmarks
Bookmark this Post
Sum of n items in an AP = n/2[First term + Last term].
n = 10 here thus we get n/2 = 10/2 here.
khalid03
How do we get the 10/2 in the sum speed?


   1   2 
Moderators:
Math Expert
110678 posts
498 posts
264 posts