Problema Solution
Eileen ran at a rate of speed of 4.8 km/h to complete a 4-km run. Sally ran at a rate of speed of 6 km/h to complete the same distance. How much longer did Eileen take to complete her run that Sally? Write your answer in minutes.
Answer provided by our tutors
d = 4 km the distance
v1 = 4.8 km/h Elleen's rate
v2 = 6 km/h Sally's rate
t1 = Elleen's time
t2 = Sally's time
Since speed = distance/time follows time = distance/speed:
t1 = d/v1
t2 = d/v2
We need to find the difference between Elleen's time and Sally's time:
t1 - t2 = d/v1 - d/v2 = d(1/v1 - 1/v2) = 4*(1/4.8 - 1/6) = 1/6 hr = (1/6)*60 = 10 min
Eileen completed the run 10 minutes after Sally.