Aptitude - Problems on Trains - Discussion
Discussion Forum : Problems on Trains - General Questions (Q.No. 30)
30.
Two stations A and B are 110 km apart on a straight line. One train starts from A at 7 a.m. and travels towards B at 20 kmph. Another train starts from B at 8 a.m. and travels towards A at a speed of 25 kmph. At what time will they meet?
Answer: Option
Explanation:
Suppose they meet x hours after 7 a.m.
Distance covered by A in x hours = 20x km.
Distance covered by B in (x - 1) hours = 25(x - 1) km.
20x + 25(x - 1) = 110
45x = 135
x = 3.
So, they meet at 10 a.m.
Discussion:
92 comments Page 10 of 10.
Mohammed Nadhil said:
7 months ago
My logic answer:
At 7, distance covered, A =0 km, B = 0 km.
At 8, distance covered A = 20 km, B =0 km.
At 9, distance covered A = 40 km, B = 25 km.
At 10, distance covered, A = 60 km, B = 50 km.
At 11, distance covered, A = 80 km, B = 75 Km.
At 12, distance covered, A =100 Km, B = 100 k.
Correct me, if my logic is wrong.
At 7, distance covered, A =0 km, B = 0 km.
At 8, distance covered A = 20 km, B =0 km.
At 9, distance covered A = 40 km, B = 25 km.
At 10, distance covered, A = 60 km, B = 50 km.
At 11, distance covered, A = 80 km, B = 75 Km.
At 12, distance covered, A =100 Km, B = 100 k.
Correct me, if my logic is wrong.
(12)
Kaushal Parmar said:
3 months ago
Your values for the distance travelled by each train are mathematically correct based on their speeds and times.
But from 10:00 a.m. onward, your reasoning ignores that the trains would have already met at 10 a.m.
Because their combined distance = 110 km, which is the total distance between A and B.
So, continuing to add distances after the meeting point doesn't make logical sense in the context of this problem.
But from 10:00 a.m. onward, your reasoning ignores that the trains would have already met at 10 a.m.
Because their combined distance = 110 km, which is the total distance between A and B.
So, continuing to add distances after the meeting point doesn't make logical sense in the context of this problem.
Post your comments here:
Quick links
Quantitative Aptitude
Verbal (English)
Reasoning
Programming
Interview
Placement Papers