travaling word equation

[purcherries]

If you drove to Austin at 70 miles per hour and returned at 50 miles per hour. What is the distance driven to Austin if total driving time was 7.2 hours?


I tried;
d=r*t
d=70+50*7.2
d=864

 

[masters]

If you drove to Austin at 70 miles per hour and returned at 50 miles per hour. What is the distance driven to Austin if total driving time was 7.2 hours?


I tried;
d=r*t
d=70+50*7.2
d=864

Hi purcherries,

Your distance is constant - the same both ways.

Let t = the time it take to travel that distance at 70 mph.

Let 7.2 - t = the time it takes to travel that distance at 50 mph.

Since the distances are the same, we have:

70t = 50(7.2 - t)

Solve for t. Then multiply t by 70 to get the distance to Austin.

 

[purcherries]

Hi thank you again,
ok so I got
t=time with the drive @ 70 mph
7.2-t is fo rthe drive @ 50
70t=50(7.2-t)
70t=360-50t
120t=360
t=3
70*3=210

 

[masters]

Hi thank you again,
ok so I got
t=time with the drive @ 70 mph
7.2-t is fo rthe drive @ 50
70t=50(7.2-t)
70t=360-50t
120t=360
t=3
70*3=210

That would be correct.