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सी.आई.एस.सी.ई.आयसीएसई ICSE Class 8

The Length, Breadth, and Height of a Cuboid Are in the Ratio 6: 5 : 3. If Its Total Surface Area is 504 Cm2; Find Its Dimensions. Also, Find the Volume of the Cuboid. - Mathematics

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प्रश्न

The length, breadth, and height of a cuboid are in the ratio 6: 5 : 3. If its total surface area is 504 cm2; find its dimensions. Also, find the volume of the cuboid.

बेरीज
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उत्तर

Let length of the cuboid = 6x

Breadth of the cuboid = 5x

Height of the cuboid = 3x

Total surface area of the given cuboid = 2 (I x b + b x h + h x l)

= 2(6x x 5x + 5x x 3x + 3x x 6x) = 2(30×2 + 15×2 + 18×2)

= 2 x 63×2 = 126x2

But we are given total surface area of the given cuboid = 504 cm2

126x2 = 504 cm2

=> `"x"^2 = 504/126`
=> x2 = 4
=> x = `sqrt(4)`
=> x = 2 cm.

Length of the cuboid = 6x = 6 x 2 = 12 cm

Breadth of the cuboid = 5x = 5 x 2 = 10cm

Height of the cuboid = 3x = 3 x 2 = 6 cm

Volume of the cuboid = l x b x h = 12 x 10 x 6 = 720 cm3

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पाठ 21: Surface Area, Volume and Capacity - Exercise 21 (A) [पृष्ठ २३८]

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सेलिना Concise Mathematics [English] Class 8 ICSE
पाठ 21 Surface Area, Volume and Capacity
Exercise 21 (A) | Q 4 | पृष्ठ २३८

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