Question 864459
Let's find out how long it will be until the two families are at the
same location.
At some distance d , we have for the first family
d = 55 km * t + 55*( 1 hour )
and for the second family, 
d = 60 km * t
So 55*t + 55 = 60*t
subtract 55t from each side
 55 = 5t
divide each side by 5
 11 = t
So for the first family d = 55*11 + 55 = 660
The first family has traveled for a total of 12 hours,
The first hour before the second family started plus 11 hours.
The second family travels the 660 miles in 11 hours.
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The two families arrive at the same time.