<PRE><B>Question 745874</B>
Jonathan leaves home at 07:45 and arrives at the office at 09:30.
 The journey is 42 miles.
:
I think you are on the right track, maybe if I just run thru it, 
it will clarify things in your mind
:
Find his travel time: 09:30 - 07:45 = 1 hr 45 min
change 1 hr 45 to hrs: 1 + 45/60 = 1.75 hrs (decimals will work here)
:
Speed = dist/time
S = {{{42/1.75}}}
S = 24 mph is the av speed
:
:
We can check that by finding the distance using a time  of 1.75 hrs and 24 mph
1.75 * 24 = 42 mi</PRE>