SOLUTION: HELP, PLZ..... A woman commutes to work first by train, then rides a bicycle from the station to her office. The train averages 50 mi/h, and she averages 15 mi/h on her bicycle. T

Algebra ->  Customizable Word Problem Solvers  -> Travel -> SOLUTION: HELP, PLZ..... A woman commutes to work first by train, then rides a bicycle from the station to her office. The train averages 50 mi/h, and she averages 15 mi/h on her bicycle. T      Log On

Ad: Over 600 Algebra Word Problems at edhelper.com


   



Question 436052: HELP, PLZ.....
A woman commutes to work first by train, then rides a bicycle from the station to her office. The train averages 50 mi/h, and she averages 15 mi/h on her bicycle. The total distance of her commute is 13 miles, and the combined trip takes 24 minutes. How far does she ride the train?

Found 2 solutions by ankor@dixie-net.com, josmiceli:
Answer by ankor@dixie-net.com(22740) About Me  (Show Source):
You can put this solution on YOUR website!
A woman commutes to work first by train, then rides a bicycle from the station to her office.
The train averages 50 mi/h, and she averages 15 mi/h on her bicycle.
The total distance of her commute is 13 miles, and the combined trip takes 24 minutes.
How far does she ride the train?
:
Let d = distance rode on the train
then
(13-d) = distance rode on the bike
:
Convert 24 min: 24/60 = .4 hrs
:
Write a time equation: Time = dist/speed
:
Train time + bike time = total time
d%2F50 + %28%2813-d%29%29%2F15 = .4 hrs
Multiply by 150
150*d%2F50 + 150*%28%2813-d%29%29%2F15 = 150(.4)
cancel the denominators
3d + 10(13-d) = 60
3d + 130 - 10d = 60
3d - 10d = 60 - 130
-7d = -70
d = +10 miles on the train
:
:
Check by finding time of each
10/50 = .2 hr
3/15 = .2 hrs
--------------
total .4 hrs which is 24 min

Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
Let t = her time spent on the train
Let d = the distance she travels on the train
Equation for train:
+d+=+50t+
Equation for bike:
+13+-+d+=+15%2A%2824%2F60+-+t%29+
+13+-+d+=+15%2A%28+.4+-+t+%29+
+13+-+d+=+6+-+15t+
By substitution:
13+-+50t+=+6+-+15t+
+35t+=+13+-+6+
+35t+=+7+
+t+=+.2+
Now find d
+d+=+50t+
+d+=+50%2A%28.2%29+
+d+=+10+
She rides the train for 10 miles
check answer:
+13+-+d+=+15%2A%2824%2F60+-+t%29+
+13+-+10+=+15%2A%28.4+-+.2%29+
+3+=+.2%2A15+
+3+=+3+