<PRE><B>Question 393883</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 21 miles per hour faster than his driving.

distance = speed *time of travel

let x= speed of auto
x+21 = speed of train
convert travel time to hours
36 min =36/60 hours = .6 hours
20 min =1/3 hours

distance auto traveled = .6x=(1/3)*(x+21)
.6x=x/3+7
1.8x=x+21
.8x=21
x=26.25 mi
distance = .6*26.25=15.75 miles=1/3(26.25+21)

ans: the distance Fritz travels to work is 15.75 miles</PRE>