Mr. Brown's Walk

Date: 09/09/97 at 17:06:01
From: Bob
Subject: Word problem

Mr. Brown takes the 5:00 p.m. train after work. His wife meets him at 
the station and drives him home. 

One day Mr. Brown took the 4:00 p.m. train. He arrived at the station 
one hour early and started walking home. His wife, unaware of his 
early arrival, left home at her usual time. She met him walking along 
the route home, picked him up, then drove him home. 

They arrived home 20 minutes earlier than usual. How long did Mr. 
Brown walk?

Date: 09/15/97 at 14:09:46
From: Doctor Rob
Subject: Re: Word problem

Let T be the length of time in hours that Mrs. Brown takes to drive
between the station and home. She must have set out at (5 - T)PM,
intending to arrive at 5PM, and to return home at (5 + T)PM.  Her 
round trip should have taken 2*T hours, but in fact took 2*T - 1/3 
hours. 

Each way to the meeting point took T - 1/6 hours, so she met Mr. Brown 
at (5-T+T-1/6)PM, or 4:50PM. Thus Mr. Brown had been walking for 50
minutes.

-Doctor Rob,  The Math Forum
 Check out our web site!  http://mathforum.org/dr.math/