Question 922063: The green train has a fuel tank of 10000 liters and burns all of its fuel in 80 hours. The blue train has a fuel tank of 15000 liters and burns all of its fuel 40 hours in order to travel twice as fast. One liter of fuel costs $3.00. Draw a graph for both trains’ fuel consumption on your own paper for reference.
a. If both trains start at the same time, how long does it take for both trains to have the same amount of fuel left? Explain how you know this answer.
b. If both trains traveled on different rails that had the same route from one station to another, which train would cost more to operate? Explain
c. Without changing the speeds of the trains, what would the rate of fuel burning in the green train need to be in order to cost as much as the blue train?
How do I answer these?
Answer by ankor@dixie-net.com(22740) (Show Source):
You can put this solution on YOUR website! The green train has a fuel tank of 10000 liters and burns all of its fuel in 80 hours.
The blue train has a fuel tank of 15000 liters and burns all of its fuel 40 hours in order to travel twice as fast.
One liter of fuel costs $3.00.
Draw a graph for both trains’ fuel consumption on your own paper for reference.
find how much fuels is used per hr for each train
10000/80 = 125 lit/hr, Green train
15000/40 = 375 lit/hr, Blue train (Red)
x = hrs, y = fuel consumption
Graph 375x, and 125x

horizontal lines show the 10000, and 15000 points
:
a. If both trains start at the same time, how long does it take for both trains
to have the same amount of fuel left? Explain how you know this answer.
let t = time in hrs for this to be true
10000 - 125t = 15000 - 375t
-125t + 375t = 15000 - 10000
250t = 5000
t = 5000/250
t = 20 hrs
Explain how you know this answer. Check it
15000 - 20(375) = 7500 liters
10000 - 20(125) = 7500
:
b. If both trains traveled on different rails that had the same route from one station to another, which train would cost more to operate?
Let's say it takes the Green train takes 6 hrs to get to a certain town.
The Blue train goes twice as fast therefore it takes 3 hrs to get to the same town
6 * 125 = 750 liters, fuel required by the Green train
3 * 375 = 1125 liter, fuel required by the Blue
Explain
:
c. Without changing the speeds of the trains, what would the rate of fuel burning in the green train need to be in order to cost as much as the blue train?
Since the Green train takes 2 hrs to go the same distance as the Blue in 1 hr
the cost per hr would be half the cost per hr of the blue
375/2 = 187.5 liters/hr
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