A train starts from a station P for another station Q at 6 p.m. at an average speed of 75 km per hour. Another train starts from station Q for station P at 8 p.m. at an average speed of 105 km per hour. If the distance between these two stations is 690 km. then at what time will the two trains meet?
Show answer & explanation
Correct answer: C
Explanation
The correct answer is option 3 i.e 11 p.m.
Train 1: Start from station P at 6 p.m. with a speed of 75 km/h
Train 2: Start from station Q at 8 p.m. with a speed of 105 km/h
Distance between P and Q = 690 km
Relative speed of two trains moving towards each other = (Speed of train 1) + (Speed of train 2)
Distance = Speed × Time
According to the question
In 2 hours, Train 1 travels distance = Speed of train 1 × time = 75 × 2 = 150 km
Remaining distance = 690 - 150 = 540 km
The relative speed = 105 + 75 = 180 km/h
Hence, The meeting time = = 3 hours
⇒ 8 p.m. + 3 hours = 11 p.m.
Hence the two trains will meet at 11 p.m.