Results 1 to 10 of 10
Like Tree12Thanks
  • 2 Post By MarkFL
  • 2 Post By DenisB
  • 1 Post By MarkFL
  • 3 Post By Plato
  • 2 Post By Debsta
  • 1 Post By MarkFL
  • 1 Post By harpazo

Thread: Cars Sold During First Quarter

  1. #1
    Super Member harpazo's Avatar
    Joined
    Sep 2014
    From
    NYC
    Posts
    995
    Thanks
    42

    Cars Sold During First Quarter

    During the second quarter of 1984, a total of 2,976,000 domestic cars were sold. If this was 24 percent greater than the number sold during the first quarter of 1984, how many were sold during the first quarter?

    My effort is shown below.

    Let c = number of cars sold during the first quarter in 1984

    0.24c = 2,976,000

    Solving for c, I got 12,400,000 cars.

    I then subtracted 2,976,000 from c.

    My answer is 9,424,000 cars sold during the first quarter in 1984. The book's answer is 2,400,000 cars.
    Follow Math Help Forum on Facebook and Google+

  2. #2
    MHF Contributor MarkFL's Avatar
    Joined
    Dec 2011
    From
    St. Augustine, FL.
    Posts
    2,312
    Thanks
    1032

    Re: Cars Sold During First Quarter

    You want:

    1.24c = 2,976,000
    Thanks from topsquark and harpazo
    Follow Math Help Forum on Facebook and Google+

  3. #3
    MHF Contributor
    Joined
    Feb 2015
    From
    Ottawa Ontario
    Posts
    2,212
    Thanks
    488

    Re: Cars Sold During First Quarter

    Quote Originally Posted by harpazo View Post
    During the second quarter of 1984, a total of 2,976,000 domestic cars were sold. If this was 24 percent greater than the number sold during the first quarter of 1984, how many were sold during the first quarter?
    Let c = number of cars sold during the first quarter in 1984
    0.24c = 2,976,000
    Solving for c, I got 12,400,000 cars.
    I then subtracted 2,976,000 from c.
    My answer is 9,424,000 cars sold during the first quarter in 1984. The book's answer is 2,400,000 cars.
    Well, you knew answer should be LESS than 2,976,000; so why did you not try again?

    Good idea to make up an easier but similar problem to see how it works; like:

    During the second quarter of 1984, a total of 110 domestic cars were sold.
    If this was 10 percent greater than the number sold during the first quarter of 1984,
    how many were sold during the first quarter?

    c + .10c = 110
    1.10c = 110
    c = 110 / 1.10 = 100

    Now using actual:
    c + .24c = 2976000
    1.24c = 2976000
    c = 2976000 / 1.24 = 2400000
    Thanks from topsquark and harpazo
    Follow Math Help Forum on Facebook and Google+

  4. #4
    MHF Contributor MarkFL's Avatar
    Joined
    Dec 2011
    From
    St. Augustine, FL.
    Posts
    2,312
    Thanks
    1032

    Re: Cars Sold During First Quarter

    Yes the problem is essentially asking you to find a number, such that when it is increased by 24%, the result is 2,976,000.
    Thanks from harpazo
    Follow Math Help Forum on Facebook and Google+

  5. #5
    MHF Contributor

    Joined
    Aug 2006
    Posts
    22,334
    Thanks
    3223
    Awards
    1

    Re: Cars Sold During First Quarter

    Quote Originally Posted by harpazo View Post
    During the second quarter of 1984, a total of 2,976,000 domestic cars were sold. If this was 24 percent greater than the number sold during the first quarter of 1984, how many were sold during the first quarter? My effort is shown below.
    Let c = number of cars sold during the first quarter in 1984. The book's answer is 2,400,000 cars.
    To harpazo, I have given you the form twice before.
    $\dfrac{\text{new }-\text{ old }}{\text{ old }}=\%$ of change.

    Solve $\dfrac{2976K-x}{x}=0.24$ SEE HERE.
    Thanks from topsquark, DenisB and harpazo
    Follow Math Help Forum on Facebook and Google+

  6. #6
    MHF Contributor
    Joined
    Oct 2009
    From
    Brisbane
    Posts
    1,189
    Thanks
    429

    Re: Cars Sold During First Quarter

    Quote Originally Posted by harpazo View Post
    During the second quarter of 1984, a total of 2,976,000 domestic cars were sold. If this was 24 percent greater than the number sold during the first quarter of 1984, how many were sold during the first quarter?

    My effort is shown below.

    Let c = number of cars sold during the first quarter in 1984

    0.24c = 2,976,000

    Solving for c, I got 12,400,000 cars.

    I then subtracted 2,976,000 from c.

    My answer is 9,424,000 cars sold during the first quarter in 1984. The book's answer is 2,400,000 cars.
    Always check the reasonableness of your answer by taking it back to the question.

    If 2,976,000 is greater than the first quarter's sales then you should expect your answer to be less than 2,976,000. Your answer can't possibly be correct, so you need to rethink the problem.
    Thanks from harpazo and topsquark
    Follow Math Help Forum on Facebook and Google+

  7. #7
    Super Member harpazo's Avatar
    Joined
    Sep 2014
    From
    NYC
    Posts
    995
    Thanks
    42

    Re: Cars Sold During First Quarter

    Quote Originally Posted by MarkFL View Post
    You want:

    1.24c = 2,976,000
    Where did 1.24 come from?
    Follow Math Help Forum on Facebook and Google+

  8. #8
    Super Member harpazo's Avatar
    Joined
    Sep 2014
    From
    NYC
    Posts
    995
    Thanks
    42

    Re: Cars Sold During First Quarter

    Quote Originally Posted by MarkFL View Post
    Yes the problem is essentially asking you to find a number, such that when it is increased by 24%, the result is 2,976,000.
    What about x + 0.24x = 2,976,000?
    Follow Math Help Forum on Facebook and Google+

  9. #9
    MHF Contributor MarkFL's Avatar
    Joined
    Dec 2011
    From
    St. Augustine, FL.
    Posts
    2,312
    Thanks
    1032

    Re: Cars Sold During First Quarter

    Quote Originally Posted by harpazo View Post
    What about x + 0.24x = 2,976,000?
    Yes, that would be correct, and then:

    $\displaystyle x(1+0.24)=2976000$

    $\displaystyle 1.24x=2976000$

    Which shows you where the 1.24 comes from.
    Thanks from harpazo
    Follow Math Help Forum on Facebook and Google+

  10. #10
    Super Member harpazo's Avatar
    Joined
    Sep 2014
    From
    NYC
    Posts
    995
    Thanks
    42

    Re: Cars Sold During First Quarter

    Thank you everyone. Good study notes here.
    Thanks from MarkFL
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. Replies: 1
    Last Post: Feb 13th 2014, 09:33 PM
  2. Replies: 0
    Last Post: Sep 4th 2013, 05:29 AM
  3. Replies: 4
    Last Post: Aug 28th 2012, 05:51 AM
  4. Replies: 2
    Last Post: May 6th 2012, 07:50 PM

/mathhelpforum @mathhelpforum