Question 910328
Re TY
153mi is the distance traveled in 1hr w/o stopping at the station.
w/o stopping at the station...{{{153mi/(1hr) = 153mph}}}
avg mph = total distance /total time
x time spent at the station(s)
{{{153mi/(1hr + highlight_green(x) ) = 72kmph}}} | Cross Multiplying to solve
72 + 72x = 153
72x = 81
x = 81/72 =  9/8 = 1.125hr = 1 1/8 hr,time spent at the stations <u>per hour traveling</u>.
checking: traveling for 2 hrs for ex
{{{306/2(1 + 1.125))}}} = 72kmph