Question

Jake’s truck was able to average only 40 mph for the first four hours of a delivery route. How long must Jake travel at a speed of 55 mph to average 50 mph for the trip?

Answer 1

Given:-

Jake’s truck was able to average only 40 mph for the first four hours of a delivery route.

To find:-

How long must Jake travel at a speed of 55 mph to average 50 mph for the trip?

Now we use speed distance formula,

The definition of that formula is the distance traveled is the product of speed and time taken.

It is expressed as,

`d=s* t`

So from this time is,

`t=(d)/(s)`

So now we substitute the values. we get,

`\begin{gathered} 50=((40*4+55t))/((t+4)) \\ 50(t+4)=160+55t \\ 50t+200=160+55t \\ 200-160=55t-50t \\ 40=5t \\ 8=t \end{gathered}`

So the required time is 8 hrs.