Question

find time taken to cover a distance of 120km at the speed of10m/sec

Answer 1

1200 seconds i e because 10 m =1 sec
100m=10 sec
1000m=100sec
12000m=1200sec

Answer 2

D=120×1000=120000 m
s=10 m/sec
t=120000/10
  =12000 sec