Respuesta :
The expression of time in terms of r is T = 85/9r. If he walked at an average speed of 3 miles per hour. Then the time taken by nick to reach the shopping mall will be 3 hours and 60 minutes.
What is speed?
The distance covered by the particle or the body in an hour is called speed. It is a scalar quantity. It is the ratio of distance to time.
We know that the speed formula
Speed = Distance/Time
Nick walked 5 miles to reach his aunt's house.
From there he traveled 8 miles to the shopping mall on a bicycle.
He traveled 80% faster on the bicycle than on foot.
Let r represent his rate of walking in miles per hour. Then the 1.8r will be the rate of cycling in miles per hour.
Then the number of hours nick took to reach the shopping mall in terms of r will be
T = t₁ + t₂
Where t₁ is the time taken to reach his aunt's house and t₂ is the time taken to reach the shopping mall from his aunt's house. Then we have
T = 5 / r + 8 / 1.8r
T = 1/r (5 + 8/1.8)
T = 85/9r
If r is 3 miles per hour, then the time taken by nick to reach the shopping mall will be
T = 85 / (9 x 3)
T = 3.15 hours
T = 3 hours and 9 minutes
More about the speed link is given below.
https://brainly.com/question/7359669
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