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Project maths mock question help

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  • 26-02-2014 4:29pm
    #1
    Hollister11
    Closed Accounts Posts: 5,482 ✭✭✭


    Can someone help me with this question from my mocks

    It's attached


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    #2
    aleatorio
    Registered Users Posts: 1,673 ✭✭✭aleatorio


    Hollister11 wrote: »
    Can someone help me with this question from my mocks

    It's attached
    Volume of a cylinder - pi r^2 h
    Volume of a cone - 1/3 pi r^2 h

    Volume of cylinder - pi (10^2)(60) = 6000pi

    Volume of 1st cone - 1/3 pi (9^2)(8) = 216pi

    6000pi - 216pi = 5784pi (remaining volume)

    Volume of 2nd cone -
    1/3 pi r^2 (18) = 5784pi (cancel pi's)
    1/3 r^2 (18) = 5784 (Multiply by 3 and divide by 18)
    r^2 = 964
    r = 31


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