Problema Solution
In the morning, Maria drove to a business appointment at 80 mph. Her average speed on the return trip in the afternoon was 70 mph. The return trip took 1/7 hr longer because of heavy traffic. How far did she travel to the appointment?
Answer provided by our tutors
let
v1 = 80 mph the average speed to the appointment
t1 = the time Maria drove to the appointment
v2 = 70 mph the average speed returning from the appointment
t2 = the time Maria drove returning from the appointment
d = the distance Maria traveled to the apointment
The return trip took 1/7 hr longer because of heavy traffic:
t2 = t1 + (1/7)
since speed = distance/time follows distance = time*speed:
v1*t1 = v2*t2
80t1 = 70t2
plug t2 = t1 + (1/7) into the last equation:
80t1 = 70(t1 + (1/7))
by solving we find:
t1 = 1 hr
click here to see the step by step solution of the equation:
d = v1*t1
d = 80*1
d = 80 mi
Maria traveled 80 miles to the appointment.