Step-by-step explanation:
a) 3km=20 minutes
times both side by 3 as 20x3 is 60mins equal 1 hour
so 3kmx3 is 9km
b) 3km is 20 mins
times both side by 6 as 20x6 is 120 mins which is equivalent to 2 hours
therefore, 3kmx6 is 18km
c) the assumption is that the longer you run means that youll jog more further so more fitness