SOLUTION: For a car moving at a constant speed, the distance traveled varies directly with the time spent driving. If such a car travels 385 miles in 7 hours, how long does it take to t

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Question 1113370: For a car moving at a constant speed, the distance traveled varies directly with the time spent driving. If such a car travels
385 miles in 7
hours, how long does it take to travel
440 miles?



Found 2 solutions by josgarithmetic, ikleyn:
Answer by josgarithmetic(39617) About Me  (Show Source):
You can put this solution on YOUR website!
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the distance traveled varies directly with the time spent driving.
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d, distance traveled
t, time of travel
r, variation constant

d=rt

r=d%2Ft

-

-------------------------------------------
If such a car travels
385 miles in 7
hours, ...
------------------------------------------

r=385%2F7=55
highlight_green%28r=55%29

------------------------------------
... how long does it take to travel
440 miles?
------------------------------------

t=d%2Fr
substitute the given values and evaluate t.

Answer by ikleyn(52788) About Me  (Show Source):
You can put this solution on YOUR website!
.
What the problem says and asks, can be presented as a proportion


385%2F7 = 440%2Fx.      (1)


From the proportion,  x = %28440%2A7%29%2F385 = 8.


Answer.  8 hours.

Solved.

Notice that each side of the proportion (1) represents the speed of the car, which is assumed to be constant.

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