Problema Solution
Steve leaves school by moped for spring vacation. Forty minutes later his roommate, Frank, notices that Steve forgot to take his camera. So, Frank decides to try to catch up with Steve by car. If Steve's average speed is 25 mph and Frank averages 45 mph, how long does it take Frank to overtake Steve?
Answer provided by our tutors
let
v1 = 25 mph the avg. speed of Steve
v2 = 45 mph the avg. speed of Frank
t = the time of Steve's travel
t - 40/60 = t - 2/3 the time of Frank's travel
since they both travel the same distance and distance = speed*time we have:
v1*t = v2(t - 2/3)
25t = 45(t - 2/3)
by solving we find
t = 1.5 hr
click here to see the step by step solution of the equation:
t - 40 min = 1.5 hr - 40 min = 90 min - 40 min = 50 min
it takes 50 min for Frank to overtake Steve.