Last visit was: 29 Apr 2026, 19:25 It is currently 29 Apr 2026, 19:25
Home
Messages
Tests
Schools
Events
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
Back to Forum
Create Topic
User avatar
Bunuel
User avatar
Math Expert
Joined: 02 Sep 2009
Last visit: 29 Apr 2026
Posts: 109,975
Own Kudos:
811,990
 [13]
Given Kudos: 105,949
Products:
GMAT Club Tests Forum Quiz
Expert
Expert reply
Active GMAT Club Expert! Tag them with @ followed by their username for a faster response.
Posts: 109,975
Kudos: 811,990
 [13]
­A train with a speed of 90 km/h crosses a bridge in 36 seconds. 26 Feb 2024, 01:22
Kudos
Add Kudos
13
Bookmarks
Bookmark this Post
00:00
Start Timer
Pause Timer
Resume Timer
Show Answer
Hide
Show
History
D
Be sure to select an answer first to save it in the Error Log before revealing the correct answer (OA)!

Difficulty:

55% (hard)

Question Stats:

74% (02:36) correct 26% (02:51) wrong based on 280 sessions

History

Date
Time
Result
Not Attempted Yet
­A train with a speed of 90 km/h crosses a bridge in 36 seconds. Another train 100 m shorter crosses the same bridge at 45 km/h. What is the time taken by the second train to cross the bridge?

(A) 32 sec
(B) 40 sec
(C) 50 sec
(D) 64 sec
(E) 72 sec­
ShowHide Answer
Official Answer
D
User avatar
Aryaa03
User avatar
Joined: 12 Jun 2023
Last visit: 19 Feb 2026
Posts: 210
Own Kudos:
287
 [3]
Given Kudos: 159
Location: India
Schools: ISB '27 (A) IIM Calcutta '26 (A) IIMA '26 (D)
GMAT Focus 1: 645 Q86 V81 DI78
Schools: ISB '27 (A) IIM Calcutta '26 (A) IIMA '26 (D)
GMAT Focus 1: 645 Q86 V81 DI78
Posts: 210
Kudos: 287
 [3]
­A train with a speed of 90 km/h crosses a bridge in 36 seconds. 26 Feb 2024, 04:39
1
Kudos
Add Kudos
2
Bookmarks
Bookmark this Post
Bunuel
­A train with a speed of 90 km/h crosses a bridge in 36 seconds. Another train 100 m shorter crosses the same bridge at 45 km/h. What is the time taken by the second train to cross the bridge?

(A) 32 sec
(B) 40 sec
(C) 50 sec
(D) 64 sec
(E) 72 sec­
Show more
­IMO-Option-D

Length of 1st Train (m) = L1
Length of 2nd Train = L1-100
Length of Bridge (m) = L2
Speed of 1st Train = S1 = 90 km/hr = 90*1000/3600 = 25 m/sec
Speed of 2nd Train = 45 km/hr = 45*1000/3600  = 12.5 m/sec

For first train to cross the entire bridge, distance to be covered = L1 + L2 at a speed of 25 m/sec
==> (L1+L2)/25 = 36
==> L1+L2 = 900 m  --(1)

As the length of 2nd train is 100 m less than that of 1st, for 2nd Train, time required to cross the bridge,
Time required, t = (L1-100+L2)/12.5
subsitute value of L1+L2 from 1st equation as 900
==>t =  (900-100)/12.5 = (800*2)/25 = 64 seconds 

For second Train­
User avatar
Themightyknight
User avatar
Joined: 15 Jan 2024
Last visit: 29 Dec 2025
Posts: 95
Own Kudos:
40
 [4]
Given Kudos: 14
GMAT 1: 610 Q47 V28
GPA: 4
WE:Real Estate (Manufacturing)
GMAT 1: 610 Q47 V28
Posts: 95
Kudos: 40
 [4]
­A train with a speed of 90 km/h crosses a bridge in 36 seconds. 26 Feb 2024, 05:01
4
Kudos
Add Kudos
Bookmarks
Bookmark this Post
Instead of solving
I went with assumption
Train A - 90km/hr time 36sec
Train B - 45km/hr time 72sec

But train is 100 Mt shorter of a but less time this 64sec

Posted from my mobile device
User avatar
Abhishek009
User avatar
Board of Directors
Joined: 11 Jun 2011
Last visit: 17 Dec 2025
Posts: 5,902
Own Kudos:
5,457
Given Kudos: 463
Status:QA & VA Forum Moderator
Location: India
GPA: 3.5
WE:Business Development (Commercial Banking)
Posts: 5,902
Kudos: 5,457
­A train with a speed of 90 km/h crosses a bridge in 36 seconds. 26 Feb 2024, 08:26
Kudos
Add Kudos
Bookmarks
Bookmark this Post
 
Bunuel
­A train with a speed of 90 km/h crosses a bridge in 36 seconds. Another train 100 m shorter crosses the same bridge at 45 km/h. What is the time taken by the second train to cross the bridge?

(A) 32 sec
(B) 40 sec
(C) 50 sec
(D) 64 sec
(E) 72 sec­
Show more
\(­90\) kmph \(= 90*\frac{5}{18} = 25\) mps
\(45\) kmpmh \(= 45*\frac{5}{18} = \frac{225}{18} = 12.5\) mps

\(T + B = 36*25\)
Or, \(T + B =  900\)

\(\frac{(T - 100 + B)}{12.5} = ?\)

We know, \(T + B = 900\) 

So, \(\frac{(900 - 100)}{12.5} = 64\), Answer must be (D)­
User avatar
PSKhore
User avatar
Joined: 28 Apr 2025
Last visit: 27 Feb 2026
Posts: 190
Own Kudos:
33
Given Kudos: 112
Posts: 190
Kudos: 33
­A train with a speed of 90 km/h crosses a bridge in 36 seconds. 24 Nov 2025, 05:31
Kudos
Add Kudos
Bookmarks
Bookmark this Post
Bunuel
­A train with a speed of 90 km/h crosses a bridge in 36 seconds. Another train 100 m shorter crosses the same bridge at 45 km/h. What is the time taken by the second train to cross the bridge?

(A) 32 sec
(B) 40 sec
(C) 50 sec
(D) 64 sec
(E) 72 sec­
Show more
Convert both the speeds into m/s
90*(5/18) = 25 m/s

The other one is 45, so it will be half of this = 12.5 m/s

Now, distance = speed*time
25*36 = 900 meters

The other distance is 100 less, so it will be 800 meters.
speed = distance/time
12.5 = 800/time
time = 64 sec

OR

By observation, if speed is halved, time taken will double, so for 100 meters less, it should be a little less than 72 (36*2), so 64
Moderators:
Bunuel
Math Expert
109975 posts
Krunaal
Tuck School Moderator
852 posts