Question

Suppose you run 2 miles from your house to a friends house at a speed of 7 mi/hr. When the time comes to return home, you are tired and walk the same 2 miles at 3 mi/hr. How long did you spend running to your friends house? How long did you spend walking home?

Answer 1

`Time = 17.143\ mins` -- When going

`Time = 40\ mins` -- When coming back

Explanation:

Given

`Speed\ to = 7mi/hr`

`Speed\ from = 3mi/hr`

`Distance = 2\ mi`

Required

Determine time taken to your friend's house

Determine time taken from your friend's house

Distance is calculated as:

`Time = (Distance)/(Speed)`

From the question, we understand that:

`Distance = 2\ mi`

When going:

`Speed\ to = 7mi/hr`

So, we have:

`Time = (2mi)/(7mi/hr)`

`Time = (2)/(7)hr`

Express in Minutes

`Time = (2)/(7) * 60`

`Time = (120)/(7)`

`Time = 17.143\ mins`

When coming back:

`Speed\ from = 3mi/hr`

`Time = (2mi)/(3mi/hr)`

`Time = (2)/(3)hr`

Express in Minutes

`Time = (2)/(3) * 60`

`Time = (120)/(3)`

`Time = 40\ mins`