SOLUTION: A car travels 360 km and comes back in total 19 hours, While returning speed of car is decreased by 4 km/hr than actual speed. What is the distance covered by car in 7.5 hours with

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Question 1152689: A car travels 360 km and comes back in total 19 hours, While returning speed of car is decreased by 4 km/hr than actual speed. What is the distance covered by car in 7.5 hours with actual speed
Found 2 solutions by ankor@dixie-net.com, josgarithmetic:
Answer by ankor@dixie-net.com(22740) (Show Source):
You can put this solution on YOUR website!
A car travels 360 km and comes back in total 19 hours, While returning speed of car is decreased by 4 km/hr than actual speed.

:
let s = actual speed
then
(s-4) = return speed
the dist both ways is the same, write a time equation; time = dist/speed
time out + time back = 19 hrs
+ = 19
multiply equation by s(s-4), cancel the denominators
360(s-4) + 360s = 19s(s-4)
360s - 1440 + 360s = 19s^2 - 76s
arrange as a quadratic equation
19s^2 - 76s - 720s + 1440 = 0
19s^2 - 796s + 1440 = 0
Use the quadratic formula; a=19 b=-796; c=1440
I got the reasonable solution of
s = 40 mph is actual speed
"What is the distance covered by car in 7.5 hours with actual speed"
7.5 * 40 = 300 mi
:
:
Check this find the actual time each way
360/40 = 9 hrs
360/36 = 10
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total time: 19 hrs

Answer by josgarithmetic(39616) (Show Source):
You can put this solution on YOUR website!