# motion prob: 'Two trains are approaching one another on a co

#### SleepyGurl

##### New member
This one I really don't know how to figure it out, here is what I know...

Two trains are approaching one another on a collision course. One is going 60 mph and the other is going 90 mph. They will collide in 20 minutes. How far apart are they now?

I know 60 and 90 mph is the rate and 20 minutes is the time? I'm just totally confused, Can someone please help? Thank you!

#### skeeter

##### Senior Member
in twenty minutes (which is 1/3 of an hour, right?) the 60 mph train travels 20 miles and the 90 mph train travels 30 miles ...

using common sense, how far apart are they?

#### SleepyGurl

##### New member
I just don't understand!

How did you figure out 20 and 30 miles per hour.

So 60 and 90 are the rate and 20 is the time? How do I know what the distance is?

Maybe I am using the wrong formula, I just don't know.

#### SleepyGurl

##### New member
Using common sense, I would say 10 miles, but not sure how they came about.

#### skeeter

##### Senior Member
there is only one "formula" ... rate times time = distance

if a train travels 60 miles in one hour, how far will it travel in 1/3 of an hour?

if a train travels 90 miles in one hour, how far will it travel in 1/3 of an hour?