the length breadth and height of a cuboid are in the ratio of 7:5:2 its volume is 35840cmsq.find its dimensions​

the length breadth and height of a cuboid are in the ratio of 7:5:2 its volume is 35840cmsq.find its dimensions​

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2 thoughts on “the length breadth and height of a cuboid are in the ratio of 7:5:2 its volume is 35840cmsq.find its dimensions​”

  1. ǫᴜᴇsᴛɪᴏɴ-:

    The length breadth and height of a cuboid are in the ratio of 7:5:2 its volume is 35840cmsq.find its dimensions

    sᴏʟᴜᴛɪᴏɴ-:

    ★Let the length,breadth and height of the cuboid be 5x , 3x and 2x respectively.

    ★We know that the volume of the cuboid is [tex]\sf{l \times b\times h}[/tex]

    ★It is given that the volume of the cuboid is [tex]\sf{35.937m^2}[/tex] , therefore.

    [tex]\sf{35.937~=~5x \times 3x\times 2x}[/tex]

    ⇝[tex]30x^3[/tex] = [tex]35.937[/tex]

    ⇝[tex]x^3[/tex] = [tex]\frac{35.937}{30}[/tex] = [tex]1.197[/tex]

    ⇝x = [tex]\sqrt{3}{1.197}[/tex]

    ⇝x = [tex]0.33[/tex]

    ★Therefore, the length l = 5x = 5 × 0.33 = 1.65,

    ★breadth b = 3x = 3 × 0.33 = 0.99 and

    ★height h = 2x = 2 × 0.33 = 0.66

    ★Now, the total surface area of cuboid is 2(lb + bh + hl),

    therefore, the total surface area with length 1.65 m, breadth 0.99 m and height 0.66 m is:

    ★A = 2[(1.65×0.99) + (0.99×0.66) + (0.99×1.65)] = 2(1.6335+0.6534+1.089) = 2×3.3759 = [tex]\sf6.7518m^2[/tex]

    ★Hence, the dimensions of cuboid is 1.65 m, 0.99 m and 0.66 m and the total surface area of cuboid is 6.7518 m

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  2. Answer:

    Step-by-step explanation:

    Answer :

    The volume of cuboid is 5670 cm³

    Step-by-step explanation :

    Let the length, breath and height of the cuboid be 7x, 6x and 5x respectively.

    According to the question ;

    Surface area of cuboid = 1926 cm²

    ⇒ 2 ( lb + bh + hl ) = 1926

    ⇒ 2 ( 7x * 6x + 6x * 5x + 5x * 7x ) = 1926

    ⇒ ( 42 x² + 30 x² + 35x² ) = 1926 / 2

    ⇒ 107 x² = 963

    ⇒ x² = 963 / 107

    ⇒ x² = 9

    ⇒ x = √9

    ⇒ x = 3

    Therefore, the length, breath and height of the cuboid are ;

    Length (l) = 7 * 3 = 21 cm.

    Breadth (b) = 6 * 3 = 18 cm.

    Height (h) = 5 * 3 = 15 cm.

    Volume of cuboid = l × b × h

    = 21 × 18 × 15

    = 5670 cm³

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