Answer:
250 km
Explanation:
Sarah traveled a total of 740 km, 2 hours more at a speed of 70 km/h than at a speed of 50 km/h. You want to know how far she traveled at 50 km/h.
Setup
The relations between time, speed, and distance are ...
distance = speed × time
time = distance/speed
If 'd' represents the distance (km) Sarah traveled by bus (at 50 km/h), then the time (hours) required was ...
time = d/50
The time at 70 km/h is 2 hours more, and the total distance is ...
total distance = (distance at 50 km/h) + (distance at 70 km/h)
740 = d + 70(d/50 +2)
Solution
Simplifying the equation, we have ...
740 = 2.4d +140
600 = 2.4d . . . . . . . . subtract 140
d = 250 . . . . . . . . . . . divide by 2.4
Sarah traveled 250 km by bus.