Question

speed of 60 km per hour for the first 1 hour and 40 km per hour for the next half hour find its average speed in kilometre per hour

Answer 1

Hii..
Here is your answer..

Solution:-
Speed 1st=60km/h
Time 1st=1hrs
So,
Distance travelled=Speed×Time
$= > 60 \times 1 \\ = > 60km$
Now,
Speed 2nd=40km/h
Time 2nd=half hrs=1/2
So,
Distance=Speed ×Time
$= > 40 \times \frac{1}{2} \\ = > 20km$
Since we know that,
$average \: speed = \frac{total \: distance}{total \: time}$
$= > \frac{80}{1 + \frac{1}{2} }$
$= > \frac{80}{ \frac{2 + 1}{2} }$
$= > \frac{80}{ \frac{3}{2} }$
$= > \frac{80 \times 2}{3}$
$= > \frac{160}{3}$
$= > 53.34$
Hence,Average speed=53.34km/h

Hope it helps uh...✌️✌️✌️

Answer 2

solution
speed -60km/hr
time-1hr
distance traveled =speed *time
=60*1
=60km

speed =40km/hr
time=1/2hr
distance =speed *time
=40*1/2=20km

average speed =total distance/total time
80/1+/1/2
8*2/3
=160/3
=53.39average speed.
Hope it's help you.