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Amanda, Bryce, and Corey enter a race in which they have to run, swim, and cycle over a marked course. Their average speeds are given in the table. Corey finishes first with a total time of 1hr 50 min. Amanda comes in second with a time of 2hr 42 min. Bryce finishes last with a time of 3hr 16 min. Find the distance (in mi) for each part of the race.

Amanda Bryce and Corey enter a race in which they have to run swim and cycle over a marked course Their average speeds are given in the table Corey finishes fir class=

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xero099

The running distance is 4.23 miles, the swimming distance is 1.98 miles and the cycling distance is 35.64 miles.

Each racer travels the same distance and the sum of the distances travelled ([tex]x[/tex]), in miles. By definition of average speed ([tex]v[/tex]), in miles per hour, we get the following system of equations:

Amanda

[tex]t_{A} = \frac{x_{R}}{v_{A, R}}+\frac{x_{S}}{v_{A,S}}+\frac{x_{C}}{v_{A,C}}[/tex] (1)

Where:

  • [tex]x_{R}[/tex] - Running distance, in miles.
  • [tex]x_{S}[/tex] - Swimming distance, in miles.
  • [tex]x_{C}[/tex] - Cycling distance, in miles.
  • [tex]v_{A,R}[/tex] - Speed of Amanda in the running distance, in miles per hour.
  • [tex]v_{A,S}[/tex] - Speed of Amanda in the swimming distance, in miles per hour.
  • [tex]v_{A,C}[/tex] - Speed of Amanda in the cycling distance, in miles per hour.
  • [tex]t_{A}[/tex] - Total time of Amanda, in hours.

Bryce

[tex]t_{B} = \frac{x_{R}}{v_{B, R}}+\frac{x_{S}}{v_{B,S}}+\frac{x_{C}}{v_{B,C}}[/tex] (2)

Where:

  • [tex]v_{B,R}[/tex] - Speed of Bryce in the running distance, in miles per hour.
  • [tex]v_{B,S}[/tex] - Speed of Bryce in the swimming distance, in miles per hour.
  • [tex]v_{B,C}[/tex] - Speed of Bryce in the cycling distance, in miles per hour.
  • [tex]t_{B}[/tex] - Total time of Bryce, in hours.

Corey

[tex]t_{C} = \frac{x_{R}}{v_{C, R}}+\frac{x_{S}}{v_{C,S}}+\frac{x_{C}}{v_{C,C}}[/tex] (3)

Where:

  • [tex]v_{B,R}[/tex] - Speed of Corey in the running distance, in miles per hour.
  • [tex]v_{B,S}[/tex] - Speed of Corey in the swimming distance, in miles per hour.
  • [tex]v_{B,C}[/tex] - Speed of Corey in the cycling distance, in miles per hour.
  • [tex]t_{B}[/tex] - Total time of Corey, in hours.

If we know that [tex]t_{A} = 2.7\,h[/tex], [tex]v_{A,R} = 10\,\frac{mi}{h}[/tex], [tex]v_{A,S} = 4\,\frac{mi}{h}[/tex], [tex]v_{A, C} = 20\,\frac{mi}{h}[/tex], [tex]t_{B} = 3.27\,h[/tex], [tex]v_{B,R} = 7.5\,\frac{mi}{h}[/tex], [tex]v_{B,S} = 6\,\frac{mi}{h}[/tex], [tex]v_{B,C} = 15\,\frac{mi}{h}[/tex], [tex]t_{C} = 1.833\,h[/tex], [tex]v_{C,R} = 15\,\frac{mi}{h}[/tex], [tex]v_{C,S} = 3\,\frac{mi}{h}[/tex] and [tex]v_{C,C} = 40\,\frac{mi}{h}[/tex], then the solution of the linear system of equations is:

[tex]\frac{x_{R}}{10} + \frac{x_{S}}{4} + \frac{x_{C}}{20} = 2.7[/tex] (4)

[tex]\frac{x_{B}}{7.5}+\frac{x_{S}}{6} +\frac{x_{C}}{15} = 3.27[/tex] (5)

[tex]\frac{x_{R}}{15}+\frac{x_{S}}{3} +\frac{x_{C}}{40} = 1.833[/tex] (6)

[tex]x_{R} = 4.23\,mi[/tex], [tex]x_{S} = 1.98\,mi[/tex], [tex]x_{C} = 35.64\,mi[/tex]

The running distance is 4.23 miles, the swimming distance is 1.98 miles and the cycling distance is 35.64 miles.

We kindly invite to check this question on systems of linear equations: https://brainly.com/question/20379472

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