Official Solution:Two trains, A and B, depart from stations X and Y respectively, and head toward each other. The speed of A is twice that of B. If when they meet, the slower train has traveled 30 km less than the faster train, what is the distance between stations X and Y? A. 30 km
B. 45 km
C. 60 km
D. 75 km
E. 90 km
Since the speed of A is twice that of B, then when they meet, A would have covered twice the distance (\(2d\)) that B would have covered (\(d\)). Given that the difference in the distance covered is 30 km, we get:
\(2d - d = 30\);
\(d = 30\) km.
The distance between stations X and Y is the sum of the distances covered by A and B by the time they meet. Hence, the total distance is \(2d + d = 3d = 90\) km.
Answer: E