Question

A boy run 10 minutes at a unform speed
of 9 km/h. At what sped should be for the
next 20 minutes so that the average speed is
12 km/hr​

Answer 1

Answer:

v1=9kmph

t1=10minutes=10/60=1/6h

v2=12kmph

t2=20minutes=20/60=1/3h

v=totaldistance covered / total time taken

v=v1t1+v2t2/t1+t2

9*1/6+12*1/3/1/3+1/6

=13.5km