Problema Solution
Ken and Karen are running in the Trent Waldron Half marathon. Ken averages 7mph. Karen averages 5 mph. If they start at the same time, how long will it be before they are half mile apart? how long will it take Ken to finish the half marathon? How long will it take Karen?
Answer provided by our tutors
let
v1 = 7 mph the average speed of Ken
v2 = 5 mph the average speed of Karen
t = the time passed running till they are 1/2 mile apart
since distance = speed*time we have:
v1*t = v2*t + 1/2
7t = 5t + 1/2
by solving we find:
t = 0.25 hr
t = 0.25*60 min
t = 15 min
click here to see the step by step solution of the equation:
since the length of the half marathon is 13 miles we have:
d = 13 mi
let
t1 = the time of Ken
t2 = the time of Karen
t1 = d/v1
t1 = 13/7
t1 = 1 hr (6/7)*60 min
t1 = 1 hr 51 min 3*60/7 sec
t1 = 1 hr 51 min 3*60/7 sec
t1 = 1 hr 51 min 26 sec is the time of Ken
t2 = d/v2
t2 = 13/5
t2 = 2 hr 0.6*60 min
t2 = 2 hr 36 min is the time of Karen