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Thread: Help with word problems involving work and distance?

  1. #1
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    Help with word problems involving work and distance?

    Hello everyone. We have homework on word problems, specifically work and distance. I've actually already answered the questions and just wanted to know if I did the right thing, because one of my answers is a fraction that seems a little bit out-of-this-world, and the other one seemed a tad bit easy to solve so I was wondering if I missed something. The questions and answers are attached as pictures.

    Thank you very much for your help! Also, I would like to apologize if this topic doesn't belong to this forum.
    Attached Thumbnails Attached Thumbnails Help with word problems involving work and distance?-math-question1.jpg   Help with word problems involving work and distance?-math-question2.jpg   Help with word problems involving work and distance?-math-question-one.jpg   Help with word problems involving work and distance?-math-question-two.jpg  
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  2. #2
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    Re: Help with word problems involving work and distance?

    Agree with 15 miles for the 1st one....plus agree it is easy!

    For the 2nd one, I get 5/12 hour = 25 minutes.

    A,B,C speeds = a,b,c.
    a = 1/1.5, b = 1/2, c = 1/2.5

    (1/2)a + (1/4)(a+b) + t(b+c) = 1 : t = "how much longer" time
    Do the rock n' roll with above to get:
    t = [1 - (3/4)a - (1/4)b] / (b + c)
    t = 5/12

    NOTE: NOT as easy as 1st one!!
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  3. #3
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    Re: Help with word problems involving work and distance?

    For the first problem you start off well, though it would be easier to follow if you said what those numbers you right down mean. When things or people work together it is their rates of work that add. Pipe A "fills a tank in 1 and 1/2 hours" so it is working at a rate of 1/(3/2)= 2/3 tank per hour and I see that here. Pipe B "fills the tank in 2 hours" so it is working at a rate of 1/2 tank per hour. Pipe C "fills the tank in 2 and 1/2 hours" so its rate is s1/(5/2)= 2/5 tank per hour. I see those fractions on your paper though you don't say what they mean.

    Pipe A is on for a total of 30+ 15= 45 min= 3/4 hour so, at 2/3 tank per hour, it fills (2/3)(3/4)= 1/2 tank. Pipe B is on for the 15 min= 1/4 hour until A is turned off and then for an additional "t" hours until the tank is full so, at 1/2 tank per hour, it fills (1/2(1/4)+ t)= 1/8+ t/2 tank. Pipe C is on for the last "t" hours so it fills (2/5)t tank. Altogether the three pipes are to fill the entire tank so that must add to "1 tank": 1/2+ 1/8+ t/2+ (2/5)t= 1 tank. Although you don't explain your work I see those numbers there. But that last "t= 45/188 hr" seems to just pop our of nowhere! Where did that come from?

    The second problem looks very simple. Jack drives at 60 mph for 10 min= 1/6 hour so he drives 10 miles. Joe drives at 30 mph for 1/6 hour so he drives 5 miles. Together then have driven 15 miles to meet. That is exactly what you have.
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  4. #4
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    Re: Help with word problems involving work and distance?

    Hello everyone. Thank you so much for helping me check my answers! For the pipe question, I realized that I made a mistake with the time of Pipe A--I wrote down "t+3/4" instead of only "3/4". After solving, I finally arrived at 5/12 or 25 minutes. Hooray! Help with word problems involving work and distance?-pipe-question.jpg
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