Wilma drove at an average speed of 35 mi/h from her home in City A to visit her sister in City B. She stayed in City B 15 hours, and on the trip back averaged 50 mi/h. She returned home 41 hours after leaving. How many miles is City A from City B

Distance = Speed * Time
D= 35 * T
D= (41-15) * 50
26*50T=1300T

Please help, Im not sure where I went wrong.

1 answer

better to use time = distance/speed, since we are adding up times here.

d/35 + 15 + d/50 = 41
17/350 d = 26
d = 26 * 350/17
d = 9100/17 = 535.29

check:

535.29/35 = 15.294
535.29/50 = 10.706
total driving time is 26 hours, as expected.