<PRE><B>Question 621503</B>
When Fritz drives to work his trip takes 36 minutes, but when he takes the train it takes 20 minutes.
 Find the distance Fritz travels to work if the train travels an average of 48 miles per hour faster than his driving.
:
Change 20 min to {{{1/3}}} hrs
Change 36 min to {{{3/5}}} hrs
:
Find his speed first
Let s = car speed
then
(s+48) = train speed
:
Write a distance equation; dist = time * speed
{{{1/3}}}(s+48) = {{{3/5}}}s
multiply both sides by 15 to get rid of the denominators; results
5(s+48) = 3(3s)
5s + 240 = 9s
240 = 9s - 5s
240 = 4s
s = 240/4
s = 60 mph in the car
Find the distance
{{{3/5}}}* 60 = 36 mi
:
Check the distance using the train (60+48) = 108 mi mph
{{{1/3}}}* 108 = 36 mi also, confirms our solution of 36 mi</PRE>