SOLUTION: kimi and amy have two different delivery routes. Kimis route is 80km and amys route is 100km. amy travels 10km/h faster than kimi and finishes 10 min earlier. What is the speed of

Algebra ->  Coordinate Systems and Linear Equations  -> Linear Equations and Systems Word Problems -> SOLUTION: kimi and amy have two different delivery routes. Kimis route is 80km and amys route is 100km. amy travels 10km/h faster than kimi and finishes 10 min earlier. What is the speed of       Log On


   

Question 1165299: kimi and amy have two different delivery routes. Kimis route is 80km and amys route is 100km. amy travels 10km/h faster than kimi and finishes 10 min earlier. What is the speed of each driver
Answer by ikleyn(52798) About Me  (Show Source):
You can put this solution on YOUR website!
.

Let x be the Kimi' speed.

Then the Amy' speed is (c+10) km/h.


Kimi's travel time is  80%2Fx  hours.

Amy's travel time is  100%2F%28x%2B10%29  hours.


The difference of travel times is 10 minutes = 1%2F6 of an hour and Amy finishes earlier.


It gives this "time" equation

    80%2Fx - 100%2F%28x%2B10%29 = 1%2F6  of an hour.


It is your setup equation.


You can solve it algebraically, by multiplying both sides by 6x*(x+10), and

reducing then to the standard form quadratic equation.


But from the equation, I just see the solution mentally:  x = 30 km/h.


ANSWER.  Kimi's rate is 30 km/h;  Ami's rate is 40 km/h.


CHECK.  Kimi's travel time is  80%2F30 = 2 2%2F3 hours.

        Ami's travel time is  100%2F40 = 2 1%2F2 hours.

        The difference is  2%2F3 - 1%2F2 = 1%2F6 of an hour, as stated.

Solved.