SOLUTION: i dont know how to do: The Rocket Coaster has 15 cars, some that hold 4 people and some that hold 6 people. There is room for 72 people altogether. How many 4-passenger cars are th

Algebra ->  Coordinate Systems and Linear Equations  -> Linear Equations and Systems Word Problems -> SOLUTION: i dont know how to do: The Rocket Coaster has 15 cars, some that hold 4 people and some that hold 6 people. There is room for 72 people altogether. How many 4-passenger cars are th      Log On


   

Question 281308: i dont know how to do: The Rocket Coaster has 15 cars, some that hold 4 people and some that hold 6 people. There is room for 72 people altogether. How many 4-passenger cars are there? How many 6-passenger cars are there?
Found 2 solutions by stanbon, richwmiller:
Answer by stanbon(75887) About Me  (Show Source):
You can put this solution on YOUR website!
The Rocket Coaster has 15 cars, some that hold 4 people and some that hold 6 people. There is room for 72 people altogether. How many 4-passenger cars are there? How many 6-passenger cars are there?
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Equations:
Car Eq:::::::: f + s = 15 cars
People Eq:::::4f +6s = 72 people
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Multiply thru the Car Equation by 4 to get:
4f + 4s = 60
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Subtract that from the People Eq and solve for "s":
2s = 12
s = 6 (3 of six-passenger cars)
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Cheers,
Stan H.

Answer by richwmiller(17219) About Me  (Show Source):
You can put this solution on YOUR website!
f+s=15
4*f+6*s=72
f=9
s=6
check
4*9+6*6=72
36+36=72
ok