SOLUTION: Your family takes a road trip to the Great Smoky Mountains. On the way you drive on highways and interstates for 6 hours. Your average speed on highways is the speed limit, 60 mph,

Algebra ->  Customizable Word Problem Solvers  -> Travel -> SOLUTION: Your family takes a road trip to the Great Smoky Mountains. On the way you drive on highways and interstates for 6 hours. Your average speed on highways is the speed limit, 60 mph,      Log On

Ad: Over 600 Algebra Word Problems at edhelper.com


    

Question 984524: Your family takes a road trip to the Great Smoky Mountains. On the way you drive on highways and interstates for 6 hours. Your average speed on highways is the speed limit, 60 mph, and your average speed on the interstate was 70 mph. Determine the number of hours and Miles travelled on each type of road if the total distance to the Great Smoky Mountains is 400 miles.
Answer by josgarithmetic(39614) About Me  (Show Source):
You can put this solution on YOUR website!

                    rate       time         distance
HIGHWY              60          y            60y
INTST               70         6-y           70(6-y)
Total                           6            400


The data can be arranged for two variables for time, but this table shows using just one variable for the two times of each kind of road. Equation to solve is the distance sum, involving the one variable, y.

60y%2B70%286-y%29=400

60y-70y=-420%2B400

10y=20

highlight%28y=2%29-----Highway time, hours
-
Interstate time is 6-2=highlight%284%29----time in hours, Interstate