SOLUTION: A stunt driver was needed at the production site of a Hollywood movie. The average speed of the stunt driver's flight to the site was 160 mph, and the average speed of the return

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Question 1197124: A stunt driver was needed at the production site of a Hollywood movie. The average speed of the stunt driver's flight to the site was 160 mph, and the average speed of the return trip was 120 mph. Find the distance of the round trip if the total flying time was 7 h.
Is how many miles for the whole round trip_____?
Found 4 solutions by ewatrrr, greenestamps, josgarithmetic, Alan3354:
Answer by ewatrrr(24785) About Me  (Show Source):
You can put this solution on YOUR website!

Hi
Let t represent time to the site:
Distance to and from are the same:  d=rt
160t = 120(7-t)
   t = 120*7/280 = 3hr
 160mph*3hr =480mi and 120mph*3hr = 480mi
Total Trip:  960mi
Wish You the Best in your Studies.


Answer by greenestamps(13198) About Me  (Show Source):
You can put this solution on YOUR website!


Informally....

The distances going and returning are the same, and the ratio of the speeds is 160:120 = 4:3; that means the ratio of the times at the two speeds is 3:4.

Then, since the total time was 7 hours, that means he spent 3 hours at 160mph on the way there and 4 hours at 120mph on the way back.

ANSWER: round trip distance = 160*3 + 120*4 = 480+480 = 960 miles

Answer by josgarithmetic(39616) About Me  (Show Source):
You can put this solution on YOUR website!
The ROUND TRIP total distance, find.

G=160, speed going
R=120, speed returning
T=7, total time traveling
x, unknown time for Going-To 
WHICH WAY        SPEED       TIME        DISTANCE
Going              G          x          Gx
Return             R          T-x        R(T-x)
Total                         T

Distance each way same;
Gx=R%28T-x%29
-
Gx=RT-Rx
Gx%2BRx=RT
%28G%2BR%29x=RT
highlight_green%28x=RT%2F%28G%2BR%29%29

Substitute the given values and evaluate x, and then evaluate 2%2AGx.

x=3
-
2%2A160%2A3
320%2A3
highlight%28960%29----------full round-trip distance

Answer by Alan3354(69443) About Me  (Show Source):
You can put this solution on YOUR website!
A stunt driver was needed at the production site of a Hollywood movie. The average speed of the stunt driver's flight to the site was 160 mph, and the average speed of the return trip was 120 mph. Find the distance of the round trip if the total flying time was 7 h.
---------------
Avg speed of a round-trip is 2%2Av%5B1%5D%2Av%5B2%5D%2F%28v%5B1%5D%2Bv%5B2%5D%29
Avg speed = 2*160*120/280 = 960/7
d = r*t = (960/7)*7 = 960 miles