<PRE><B>Question 1071513</B>
A man walks at the rate of 4 miles per hour.
 How far can he walk into the country and ride back on a trolley that travels at the rate of 20 miles per hour, if he must be back home 3 hours from the time he started?
:
let d = the one-way distance
:
Write a time equation. time = dist/speed
walk time + ride time = 3 hrs
{{{d/4}}} + {{{d/20}}} = 3
multiply equation by 20, cancel the denominators
5d + d = 60
6d = 60
 d = 10 mi he walks into the country
:
:
Check this, find the actual time walking and riding
10/4 = 2.5 hrs
10/20 = .5 hrs
----------------
tot time 3 hrs
 </PRE>