Instructions

Study the table and answer the given questions.
Data regarding number of students studying in various streams in various Universities
(St. Christ, P.D. and Kelly), in the year 2012

None: Total students = Female students + Male students

Question 65

# The distance between two cities (M and N) is 569 km. A train starts from city M at 8 a.m. and travel towards city N @ 53 km/h. Another train starts from city N at 9 am and travel towards city M @ 76 km/h. At what time will the trains meet ?

Solution

NOTE ;- When two objects travel in opposite directions, their relative speed is sum of their individual speeds.

When they travel in same direction, their relative speed is the difference of their respective speeds.

Distance between the two cities = 569 km

1st train starts at 8 a.m. travelling at 53 km/h. Thus, it will travel 53 km in 1 hr.

Thus, at 9 a.m., remaining distance between the two trains = 569-53 = 516

Relative speed = 53+76 = 129 km/h

Time when the two trains meet = 516/129 = 4 hrs [ time = distance/time]

Thus, both trains will meet after 4 hrs after 9 a.m. => 1 p.m.