Question 61205
This problem requires careful reading. 
Right away it says that Bob maintains the same speed. That
means he doesn't stop or slow down or speed up.
There's a stopwatch on him, and it says he traveled for .5 hour
and he was 77.5 miles from home. After 1 hour he was 55 miles
from home.
This is where you have to read carefully
after .5 hour he was 77.5 miles from home, and then, after 
ANOTHER .5 hour he was 55 miles from home. So, during the 2nd 
.5 hour, he covered 77.5 - 55 = 22.5 miles. That means his
rate of travel is 22.5 / .5 or 45 miles per hour.
D = total distance Bob traveled
x = time spent travelling
D = r*x
D = 45x
Now I ask, How long did it take Bob to travel the 77.5 miles to
home after he was on the road for .5 hr?
77.5 = 45x
x = 1.722 hours
That means it took Bob .5 + 1.722 = 2.222 hours to get home
You can figure it the other way, too.
After 1 hour, Bob was 55 miles from home. His time to cover
55 miles was
55 = 45x
x = 1.222 hours
That means he took 1 + 1.222 hours = 2.222 hours to get home
(agrees with my 1st result)
How many minutes is .222 hours?
.222*60 min/hr = 13.333 minutes
How many seconds is .333 minutes?
.333*60 sec/min = 20 seconds.
Bob took 2 hours 13 minutes and 20 seconds to get home