1. Length of cuboidal pit l = 8 m, breadth b = 6 m and height h = 3 m. Volume of cuboidal pit = lbh = 8 × 6 × 3 = 144 m³ Cost of digging at the rate of Rs 30 per m³ = Rs 144 × 30 = Rs 4320 Hence, the cost of digging the cuboidal pit is Rs 4320.

    Length of cuboidal pit l = 8 m, breadth b = 6 m and height h = 3 m.
    Volume of cuboidal pit = lbh = 8 × 6 × 3 = 144 m³
    Cost of digging at the rate of Rs 30 per m³ = Rs 144 × 30 = Rs 4320
    Hence, the cost of digging the cuboidal pit is Rs 4320.

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  2. Length of cuboidal tank l = 2.5 m, depth h = 10 m and volume V = 50000 litres = 50 m³ Let, the breadth of cuboidal tank = b m Volume of cuboidal tank = lbh ⇒ 50 = 2.5 × b × 10 ⇒ b = 50/2.5×10 = 2 m Hence, the breadth of cuboidal tank is 2 m.

    Length of cuboidal tank l = 2.5 m, depth h = 10 m and volume V = 50000 litres = 50 m³
    Let, the breadth of cuboidal tank = b m
    Volume of cuboidal tank = lbh
    ⇒ 50 = 2.5 × b × 10
    ⇒ b = 50/2.5×10 = 2 m
    Hence, the breadth of cuboidal tank is 2 m.

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  3. Length of tank l = 20 m, Breadth b = 15 m and height h = 6 m Volume of tank = lbh = 20 × 15 × 6 = 1800 m³ = 1800 × 1000 = 1800000 litres Daily requirement of water = 150 litres Therefore, the requirement of 4000 person for one day = 150 × 4000 = 600000 litres Hence, the number of days to consume allRead more

    Length of tank l = 20 m, Breadth b = 15 m and height h = 6 m
    Volume of tank = lbh = 20 × 15 × 6 = 1800 m³ = 1800 × 1000 = 1800000 litres
    Daily requirement of water = 150 litres
    Therefore, the requirement of 4000 person for one day = 150 × 4000 = 600000 litres
    Hence, the number of days to consume all water of tank
    Volume of tank/Volume of water for 4000 person for one day
    = 1800000 litres/600000 litres = 3

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  4. Length of godown L = 40 m, breadth B = 25 m and height H = 15 m Volume of godown = LBH = 40 × 25 × 15 = 15000 m³ Length of crate l = 1.5 m, breadth b = 1.25 m and height h = 0.5 m Volume of crate = lbh = 1.5 × 1.25 × 0.5 = 0.9375 m³ Now, Number of crates to be stored in godown = Volume of godown/VolRead more

    Length of godown L = 40 m, breadth B = 25 m and height H = 15 m
    Volume of godown = LBH = 40 × 25 × 15 = 15000 m³
    Length of crate l = 1.5 m, breadth b = 1.25 m and height h = 0.5 m
    Volume of crate = lbh = 1.5 × 1.25 × 0.5 = 0.9375 m³
    Now,
    Number of crates to be stored in godown = Volume of godown/Volume of 1crate
    = 15000 m³/0.9375 m³ = 10666.67
    Hence, maximum of 10666 crates can be placed in the godown.

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  5. Side of larger cube A = 12 cm. Therefore, volume = A³ = 12 × 12 × 12 = 1728 cm³ According to question, Volume of smaller cube a³ = Volume of larger cube/8 = 1728 cm³/8 = 216 cm³ ⇒ a³ = 216 cm³ ⇒ a = √216 = 6 cm Hence, the side of new cube is cm. Now, ratio of surface areas of two cubes = Surface areRead more

    Side of larger cube A = 12 cm. Therefore, volume = A³ = 12 × 12 × 12 = 1728 cm³
    According to question, Volume of smaller cube
    a³ = Volume of larger cube/8 = 1728 cm³/8 = 216 cm³
    ⇒ a³ = 216 cm³ ⇒ a = √216 = 6 cm
    Hence, the side of new cube is cm.
    Now,
    ratio of surface areas of two cubes = Surface area of large cube/Surface area of smaller cube = 6A²/6a² = A²/a² = 12²/6² = 144/36 = 4:1

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