Please help... math

Discussion in 'Community Discussion' started by gregdrummeraz, Jun 16, 2008.

  1. gregdrummeraz macrumors 6502

    Joined:
    Jun 7, 2007
    Location:
    Glendale, az
    #1
    The St. Louis River tank is a trapezoidal prism. The height of the trapezoidal base is 24 ft, and the two bases are 3 ft and 7 ft. If the height of the tank is 3 ft 6 in., what is the volume of the tank?


    I'm Stumped... again. :confused::eek:
     
  2. dukebound85 macrumors P6

    dukebound85

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    Location:
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    #2
    height times average of bases is the area

    then times it by the depth to get volume
     
  3. siurpeeman macrumors 603

    siurpeeman

    Joined:
    Dec 2, 2006
    Location:
    the OC
    #3
    more generally, the volume of a prism can be found by multiplying the base area and the height of the prism. and as the above poster mentioned, the area of the trapezoid is the average of the bases times the height.
     
  4. gregdrummeraz thread starter macrumors 6502

    Joined:
    Jun 7, 2007
    Location:
    Glendale, az
    #4
    Here were my choices.

    420ft^3
    400ft^3
    380ft^3
    375ft^3
     
  5. dukebound85 macrumors P6

    dukebound85

    Joined:
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    #5
    Edit: just use the above equations to get answer

    it is one of the choices lol
     
  6. TuffLuffJimmy macrumors G3

    TuffLuffJimmy

    Joined:
    Apr 6, 2007
    Location:
    Portland, OR
    #6
    Four twenty!

    maybe you should have listened to what the other posters said and tried to learn something for yourself.
     
  7. gregdrummeraz thread starter macrumors 6502

    Joined:
    Jun 7, 2007
    Location:
    Glendale, az
    #7
    And I think it is either 380 or 420..


    idk.. I really suck at this kind of math.
     
  8. dukebound85 macrumors P6

    dukebound85

    Joined:
    Jul 17, 2005
    Location:
    5045 feet above sea level
    #8
    for your benefit

    A=3.5 *(7+3)/2
    A=17.5ft^2


    V= 24 *A=24*17.5
    V=420ft^3


    I hope you get the hang of following equations as if you go into any scientific major in college and cant do this, you are well in trouble lol
     
  9. TuffLuffJimmy macrumors G3

    TuffLuffJimmy

    Joined:
    Apr 6, 2007
    Location:
    Portland, OR
    #9
    apparently you're not too great at reading threads either...


    the answer has been given
     
  10. dukebound85 macrumors P6

    dukebound85

    Joined:
    Jul 17, 2005
    Location:
    5045 feet above sea level
    #10
    to be fair, we all posted at 1:44 :p
     

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