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Denise has 3 hours to spend training for an upcoming race. She completes her training by running full speed the distance of the race and walking back the same distance to cool down. If she runs at a speed of 8mph and walks back at a speed of 2mph, how long should she plan to spend walking back?

Respuesta :

Answer:

Denise should plan to spend 36 minutes walking back.

Step-by-step explanation:

Let 'x' reflect the amount of time spent running in hours, then 3-x represents the time spent walking in hours.

here , we know,

           [tex]Distance= Speed \times time[/tex]

Given the values ,

[tex]Distance= 8x[/tex]  

[tex]speed=2mph[/tex]

[tex]Time=(3-x)hours[/tex]

Now , putting these values ,

[tex]8x=2(3-x)[/tex]

[tex]8x=6-2x[/tex]

[tex]10x=6[/tex]

[tex]x=\frac{6}{10}[/tex]

[tex]x=\frac{3}{5}[/tex]

[tex]\frac{3}{5} \times 60[/tex] = 36minutes (converting hours into minutes that is 1 hour = 60 minutes )

Hence , the answer is 36 minutes .