SOLUTION: Rohan travels 600 km from his home partly by train and partly by car. He takes eight hours if he travels 120 km by train and rest by car. he takes 20 minutes more if he travels 200

Algebra ->  Customizable Word Problem Solvers  -> Travel -> SOLUTION: Rohan travels 600 km from his home partly by train and partly by car. He takes eight hours if he travels 120 km by train and rest by car. he takes 20 minutes more if he travels 200      Log On

Ad: Over 600 Algebra Word Problems at edhelper.com


    

Question 602452: Rohan travels 600 km from his home partly by train and partly by car. He takes eight hours if he travels 120 km by train and rest by car. he takes 20 minutes more if he travels 200 km by train and rest by car. find the speed of train and car
Answer by lwsshak3(11628) About Me  (Show Source):
You can put this solution on YOUR website!
Rohan travels 600 km from his home partly by train and partly by car. He takes eight hours if he travels 120 km by train and rest by car. he takes 20 minutes more if he travels 200 km by train and rest by car. find the speed of train and car.
**
let x=speed of train
let y=speed of car
travel time=distance/speed
..
120/x+480/y=8
200/x+400/y=8+1/3=25/3
..
let u=1/x
let v=1/y
..
120u+480v=8
200u+400v=25/3
..
120u+480v=8
600u+1200v=25
..
600u+2400v=40 (multi. by 5)
600u+1200v=25
subtract
1200v=15
v=15/1200
y=1/v=1200/15=80
..
120u=8-480v=8-(480*15/1200)=8-6=2
u=2/120=1/x
x=120/2=60
..
ans:
speed of train=60 km/hr
speed of car=80 km/hr