SOLUTION: Two boys on bicycles start from the same place and ride in opposite directions. One rides twice as fast as the other one. in 3 hours, they are 27 kilometers apart. what is the rate

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Question 384773: Two boys on bicycles start from the same place and ride in opposite directions. One rides twice as fast as the other one. in 3 hours, they are 27 kilometers apart. what is the rate of speed for each boy?
Found 2 solutions by stanbon, ewatrrr:
Answer by stanbon(75887) About Me  (Show Source):
You can put this solution on YOUR website!
Two boys on bicycles start from the same place and ride in opposite directions. One rides twice as fast as the other one. in 3 hours, they are 27 kilometers apart. what is the rate of speed for each boy?
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1st rider data:
rate = x kmh ; time = 3 hrs ; distance = 3x km
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2nd rider data:
rate = 2x kmh ; time = 3 hrs ; distance = 3(2x) = 6x km
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Equation:
distance + distance = 27 km
3x + 6x = 27
9x = 27
x = 3 km/h (1st rider's speed)
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2x = 6 km/h (2nd rider's speed)
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cheers,
Stan H.

Answer by ewatrrr(24785) About Me  (Show Source):
You can put this solution on YOUR website!


Hi,         

Let x and 2x represent  their respective speeds

D = r*t

 3hr*x + 3hr*2x = 27km

     9hr*x = 27km

      x = 3kmph

  3kmph and 6kmph the speeds for the two boys.



CHECKING Our Anwser

 3hr*3kmph + 3hr*6kmph = 27km