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A jogger begins her workout by jogging to the​ park, a distance of 21 miles. She then jogs home at the same​ speed, but along a different route. This return trip is 28 ​miles, and her time is one hour longer. Find her jogging speed. Complete the accompanying chart and use it to find her jogging speed. Let r be the jogging speed.

Respuesta :

Answer:

She jogs at a speed of 7mph

Step-by-step explanation:

Distance to the Park=21 miles

Let her Speed be r( miles/hour)

Time taken= t hour

Therefore her Speed, r= 21/t .....(I)

Distance on her Return Trip= 28 miles

On her return trip, the time is 1 hour longer, therefore time taken=(t+1) hour

Speed , r =28/(t+1) ........(ii)

Since her speed is the same

21/t=28/(t+1)

Cross Multiplying

21(t+1)=28t

21+21t=28t

21=28t-21t

21=7t

Therefore her time, t=3

From (I),

Speed r= 21/t= 21/3 =7 miles per hour

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