Can you help me on this question?

Question

Karin is going on a trip to Chicago. First, she drives in her car for 1.5 hours to the train station. Then she gets on a train which takes and additional 2 hours to get to Chicago. Suppose that Karen travels twice as fast in her car as the train, and the total distance to Chicago is 150 miles. What is the speed that Karen drives and what is the speed of the train

Answer 1

Megan,

 

The basic equation you are using here is Rate*Time=Distance.

 

In the car, Karin went twice as fast as the train, so I used the trains rate as r and the cars as 2r.  The times are given.

 

So the distance driven in the car is 2r*1.5

The distance in the train is r*2

 

Adding these two together yields the final distance of 150 miles.

 

2r(1.5)+2r=150      [Now solve for r]

3r+2r=150

5r=150

r=30      [r was the rate of the train]

 

rate of the car=2r=2(30)=60

 

I hope this helps.