Help me with this formula please

Discussion in 'General' started by bahookahjoe18, May 28, 2012.

  1. Hey Blades, I'm trying to find a variable but I can't define my formula. This is real life application algebra for all young Blades that see this and question their math teachers.

    1 ton of asphalt spread 2.5 inches thick will cover 80 square feet of driveway. If it is spread 3 inches thick, how many square feet will it cover?

    Please show me the formula too.
     
  2. #2 itsamesmokio, May 28, 2012
    Last edited by a moderator: May 28, 2012
    Pretty simple formula, cause you're doing height x square feet (length x width), so really you're dealing with volume, or cubic feet. The volume is constant, so just use a ratio
    2.5*80=3*x
    200=3x
    200/3=x
    66.67=x
    So, ~67 ft^2
     
  3. My formula is hire a contractor and let him handle all that.
     
  4. The variable is how many inches thick you spread it. Formula is 2000lb/80sqft= 25lb per 12 square inches 80sqft

    12*12*2.5 = 360 cubic inches per square foot 25lb/360cubic inches = .069444(bar)lb per cubic inch

    then lets see...
    and then 12*12*3 = 432 square inches per foot

    360cubic inches per foot * 80 ft = 28,800 cubic inches total
    28,800cubic inches * .069444(bar)lb per cubic inch = 2klb(2 thousand pounds
    (432* X) * .069444(bar)lb per cubic inch = 2k
    so then 2000/ .069444(bar) = 28,800/ 432 = 66.6666667 square feet total.


    and well fuck... now i just figured out an easier way to do it just go :

    2000/2.5 = 800 which equals 80
    800/ 80 gives a ratio of 10

    2000/3 = 666.6666667 which equal X
    666.6666667/ 10 = 66.66666667 feet
     
  5. You don't even need weight. It's a volume problem.
     

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