Question

pranav went to the bank at the speed of 60 km per hour while returning from his home he cover the half of the distance at the speed of 10 kilometre but suddenly realise that was getting late so increase the speed and reached the home by covering rest half of distance at a speed of 30 kilometre per hour the average speed of the Pranav in the whole length of the journey is

Answer 1

I assume total distance is 2d I have already clearly mentioned in figure

Answer 2

Answer:

Average Speed of Pranav in whole journey is 24 km/hr

Step-by-step explanation:

Step 1:    Let distance between Pranav home and hospital = dd km

Step 2: Total distance traveled by Pranav = d + d/ 2+d/2=2d km

Average Speed=total distance/total time

Step 3: Total time taken from Pranav Home to Bank=2d/(t1+t2+t3)  [given time t1=60,t2=20,t3=30]

=2d/(d/60+d/20+d/30)

Least common multiple=120

Step 4: To calculate the Average speed of Pranav whole journey  

=2d/(2d+6d+2d)/120

=2d/10 x d/120

=120 x 2/10

=24 km/hr