A train left Shawnee traveling due west at 90 miles per hour

A train left Shawnee traveling due west at 90 miles per hour. A car left Shawnee at the same time traveling due east at 60 miles per hour. How much time will pass before the train and car are 405 miles apart?

Solution

rate*time=distance
and t= time
At first glance it might seem we don\'t have enough info.
but we are told the distance 405 and the two speeds
the time is the same for both car and train
so
t*90+t*60=405
t*(90+60)=405
t(150)=405
t=405/150
t=27/10
t=2.7 hours or 2 hrs 42 minutes
Are you sure the distance is not 450?
IF it were 450 then we have
t*(90+60)=450
t*150=450
t=3 hours