COMEDK Exam 2014 Solved Paper

The given situation is shown below

Let the distance between the two places is x km.
∴AM=MB=

x

2

km
Time taken by the car to cover first half (AM) with the speed of 40km∕h is given as
t1=

AM

40

=

x 2

40

=

x

80

h
Similarly, time taken by the car to cover second half (MB) with the speed of 60km∕h is given as
t2=

MB

60

=

x 2

60

=

x

120

h
∴ Average speed of car,
vavg=

Total‌distance‌travelled

Total‌time‌taken

=

x

x 80 + x 120

=

x

5x 240

=

240

5

=48km∕h