Joan and her brother justin left a hotel at the same time, driving in opposite directions at constant rates. after traveling for 4 hours, they were 480 miles apart. if justin drove 10 miles per hour faster than joan, how fast did joan drive?

Joan drive with a speed of 55 miles per hour.

Step-by-step explanation:

Given:- Travelling time (t) = 4 hours.

Travelled distance (d) = 480 miles.

Speed of Justin is 10 miles per hour faster than Joan.

To find:- Speed of Joan = ?

Solution:-

Let speed of Joan be x,

therefore speed of Justin = x+10          ---------------(from given)

Now, Total speed of Joan and Justin = x+x+10

Total speed of Joan and Justin = 2x+10 ------------(1)

Now formula for speed is,

Speed =

                       -------------(from 1 and given)

as x is the speed of Joan,

Therefore Joan drive with a speed of 55 miles per hour.

step-by-step explanation:

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