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Homework Help: Simple distance traveled problem

  1. Dec 21, 2008 #1
    1. The problem statement, all variables and given/known data
    A boy walks at an average speed of 3 miles per hour to his school, and then runs back at an average speed of 5 miles per hour along the same route. The total travel time is 1 hour. What was the total distance traveled?

    3. The attempt at a solution
    OK it's a practice question I saw in my SAT prep book, and I feel soooo incredibly stupid to not be a ble to solve this. The answer is 3.75 miles, btw.

    d1 = d2
    dt = d1 + d2
    t1 + t2 = 1 hr
    d1 = v1t1
    d2 = v2(1-t1)

    dt = v1t1 + v2-v2t1
    dt = 3t1 + 5 - 5t1

    Then I get stuck here.

    Pretty sure I am over complicating the problem, so could somene help me?
     
  2. jcsd
  3. Dec 21, 2008 #2

    Dick

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    Homework Helper

    Let the distance to school be d. Then d/v1+d/v2=1hr. Solve for d. The total distance travelled is then 2*d.
     
    Last edited: Dec 21, 2008
  4. Dec 21, 2008 #3
    Ohh, ok I didn't think about redefining t1.

    Thanks.
     
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