Question

The average speed of a bicyclist, if he covers first 5km
with a speed 15km/hr and next 5km with speed10km/hr, would be
(a) 12.5 km/hr
(b) 12 km/hr
(c) 15 km/hr
(d) 6 km/hr​

Answer 1

Answer:

12km/h

Explanation:

d=st

T1= 5/15

T2=5/10

total distance =5+5

                      =10km

total time=5/15+5/10

                 =1/3+1/2

                   =(2+3)/6

                     =5/6hours

average speed =total distance/total time

                        =10/(5/6)km/h

                       =60/5km/h

                        =12km/h