SOLUTION: Two trains leave towns 692 mi apart at the same time and travel toward each other. One train travels 21/mi/h slower than the other. If they meet in 4 hours, what is the rate of e

Algebra ->  Coordinate Systems and Linear Equations -> SOLUTION: Two trains leave towns 692 mi apart at the same time and travel toward each other. One train travels 21/mi/h slower than the other. If they meet in 4 hours, what is the rate of e      Log On


   



Question 1112890: Two trains leave towns 692 mi apart at the same time and travel toward each other. One train travels
21/mi/h slower than the other. If they meet in 4 hours, what is the rate of each train?

Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
Let +s+ = the speed of the faster car in mi/hr
+s+-+21+ = the speed of the slower car
---------------------------------------------
You can think of this as one of the cars travelling
at the sum of their speeds and the other one
standing still
+692+=+%28+s+%2B+s+-+21+%29%2A4+
+4%2A%28+2s+-+21+%29+=+692+
+8s+-+84+=+692+
+8s+=+776+
+s+=+97+
and
+s+-+21+=+76+
--------------------
The faster train's rate is 97 mi/hr
The slower train's rate is 76 mi/hr
-----------------------------------
check:
+d%5B1%5D+=+97%2A4+
+d%5B1%5D+=+388+ mi
and
+d%5B2%5D+=+76%2A4+
+d%5B2%5D+=+304+
and
+d%5B1%5D+%2B+d%5B2%5D+=+388+%2B+304+
+d%5B1%5D+%2B+d%5B2%5D+=+692+
OK