SOLUTION: A person takes a trip, driving with a constant speed 94 km/h except for a 80 min rest stop. If the person's average velocity is 78 km/h, how far is the trip? Answer in units of km.

Algebra ->  Customizable Word Problem Solvers  -> Travel -> SOLUTION: A person takes a trip, driving with a constant speed 94 km/h except for a 80 min rest stop. If the person's average velocity is 78 km/h, how far is the trip? Answer in units of km.      Log On

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Question 758858: A person takes a trip, driving with a constant speed 94 km/h except for a 80 min rest stop. If the person's average velocity is 78 km/h, how far is the trip? Answer in units of km.

Found 2 solutions by josgarithmetic, josmiceli:
Answer by josgarithmetic(39614) About Me  (Show Source):
You can put this solution on YOUR website!
ACTIVITY____________rate________time hours____distance km.
DRIVING______________94________(h)___________94h
RESTING______________0_________(1&1/3)_________0

Total distance divided by total time gives the average rate:
highlight%28%2894h%29%2F%28h%2B1%261%2F3%29=78%29
Solve for h= time in hours, and then you can compute the value for distance, 94h.

Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
Let +t+ = time for trip in hrs while driving
Average speed = ( total distance ) / ( total time )
Average speed = +78+ km/hr
Total distance = +94t+
Total time = +t+%2B+80%2F60+
Total Time = +t+%2B+4%2F3+
----------------------------
Now I can say:
Average speed = +%28+94t+%29+%2F+%28+t+%2B+4%2F3+%29+
+78+=+%28+94t+%29+%2F+%28+t+%2B+4%2F3+%29+
+78%2A%28+t+%2B+4%2F3+%29+=+94t+
+78t+%2B+104+=+94t+
+16t+=+104+
+t+=+6.5+
The time spent driving is +6.5+ hrs
+d+=+94t+
+d+=+94%2A6.5+
+d+=+611+
The trip is 611 miles
check:
Average speed = ( total distance ) / ( total time )
+78+=+611+%2F+%28+6.5+%2B+4%2F3+%29+
+78%2A7.8333+=+611+
+611+=+611+
OK