Two trains T1 T2, which are 539 km apart start at the same time, move towards each other. They just complete crossing each other in 3hrs 20 mins. fIND THE DIFFERENCE BETWEEN THE LENGTHS OF THE TWO TRAINS, GIVEN THAT THEIR LENGTHS ARE IN THE RATIO 2:3 AND THEIR SPEEDS ARE 25M/S and 20m/s respectively
A) 100m
B) 200m
C) 500m
D) 150m
OA is
B
5-Day Free Trial
5-day free, full-access trial TTP
Available with Beat the GMAT members only code
MORE DETAILS
time speed dist
This topic has expert replies
-
mitaliisrani
- Senior | Next Rank: 100 Posts
- Posts: 56
- Joined: Sun Mar 21, 2010 11:06 am
GMAT/MBA Expert
-
Rahul@gurome
- GMAT Instructor
- Posts: 1179
- Joined: Sun Apr 11, 2010 9:07 pm
- Location: Milpitas, CA
- Thanked: 447 times
- Followed by:88 members
Solution:
Let the length of the trains be 2x and 3x.
So the distance being covered in 3hrs 20 minutes is 539 + 2x +3x = 539+5x.
Their speeds are 25m/s and 20m/s.
Or relative speed is (25+20) = 45m/s = 162km/hr since the two trains are moving in opposite directions.
So (539+5x)/162 = 3 + 20/60 hrs = 10/3
Or 539 + 5x = 540.
Or x = 1/5 km = 200m.
The correct answer is (B).
Let the length of the trains be 2x and 3x.
So the distance being covered in 3hrs 20 minutes is 539 + 2x +3x = 539+5x.
Their speeds are 25m/s and 20m/s.
Or relative speed is (25+20) = 45m/s = 162km/hr since the two trains are moving in opposite directions.
So (539+5x)/162 = 3 + 20/60 hrs = 10/3
Or 539 + 5x = 540.
Or x = 1/5 km = 200m.
The correct answer is (B).
Rahul Lakhani
Quant Expert
Gurome, Inc.
https://www.GuroMe.com
On MBA sabbatical (at ISB) for 2011-12 - will stay active as time permits
1-800-566-4043 (USA)
+91-99201 32411 (India)
Quant Expert
Gurome, Inc.
https://www.GuroMe.com
On MBA sabbatical (at ISB) for 2011-12 - will stay active as time permits
1-800-566-4043 (USA)
+91-99201 32411 (India)
