Question

a bus travels a distance of 120 km with a speed of 40 km per hour and returns with a speed of 30 km per hour calculate the average speed for the entire journey

Answer 1

Average speed = Total distance covered /total time taken

.

Here we are not given time , so first we will find time :

.

Speed =distance/time

.

Therefore,

Time =distance /speed

.

T1 =120/40= 3 sec

.

T2=120/30 =4 sec

.

.

.

Now , put the value of time in the main formula ,

.

A .s. =120 +120 /4+3

=240 / 7

.

=34.285 km/h

Answer 2

t1=d/s
= 120/40
= 3h

t2 =d/s
=120/30
=4h

average speed= total distance traveled
---------------------------------
total time taken
= 120+120
---------
4+3
=240
--------
7
34.28



HOPE IT HELPS U. ..........