1. Radius of cone r = 6 m and height h = 8 m let, the slant height = l m We know that, l² = r² + h² ⇒ l² = 6² + 8² = 36 + 64 = 100 ⇒ l = √100 = 10 m Area of tarpaulin to make the tent = πrl = 3.14 × 6 × 10 = 188.40 m² Let, the length of 3 m wide tarpaulin = L Therefore, the area of tarpaulin required =Read more

    Radius of cone r = 6 m and height h = 8 m
    let, the slant height = l m
    We know that, l² = r² + h²
    ⇒ l² = 6² + 8² = 36 + 64 = 100
    ⇒ l = √100 = 10 m
    Area of tarpaulin to make the tent = πrl
    = 3.14 × 6 × 10 = 188.40 m²
    Let, the length of 3 m wide tarpaulin = L
    Therefore, the area of tarpaulin required = 3 × L
    According to question,
    3 × L = 188.40
    ⇒ L = 188.40/3 = 62.80 m
    Extra tarpaulin for stitching margins and wastage = 20 cm = 0.20 m
    Therefore, the total lenght of tarpaulin = 62.80 + 0.20 = 63 m
    Hence, the length of 3 m wide tarpaulin is 63 m to make the tent.

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  2. Radius of conical tomb r = 14/2 = 7 m and slant height l = 25 m Curved surface area of conical tomb = πrl = 22/7 × 7 × 25 = 550 m² Cost of white washing at the rate of Rs 210 per 100 m² = Rs 550 × 210/100 = Rs. 1155 Hence, the cost of white washing curved surface area is Rs 1155.

    Radius of conical tomb r = 14/2 = 7 m and slant height l = 25 m
    Curved surface area of conical tomb = πrl
    = 22/7 × 7 × 25 = 550 m²
    Cost of white washing at the rate of Rs 210 per 100 m² = Rs 550 × 210/100 = Rs. 1155
    Hence, the cost of white washing curved surface area is Rs 1155.

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  3. Radius of right circular cone r = 7 cm and height h = 24 cm Let, the slant height = l m We know that l² = r² + h² ⇒ l² = 7² + 24² = 49 + 576 = 625 ⇒ l = √625 = 25 cm Area of sheet required to make 1 cap = πrl = 22/7 ×7 × 25 = 550 cm² Therefore, area of sheet required to make 10 such caps = 10 × 550Read more

    Radius of right circular cone r = 7 cm and height h = 24 cm
    Let, the slant height = l m
    We know that l² = r² + h²
    ⇒ l² = 7² + 24² = 49 + 576 = 625
    ⇒ l = √625 = 25 cm
    Area of sheet required to make 1 cap = πrl
    = 22/7 ×7 × 25 = 550 cm²
    Therefore, area of sheet required to make 10 such caps = 10 × 550 = 5500 cm²
    Hence, area of sheet to make 10 such caps is 5500 cm²

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  4. Total surface area of cylindrical Petrol storage tank = 2πr(r + h) = 2 × 22/7 × 2.1 × (2.1 + 4.5) = 2 × 22/7 × 2.1 × 6.6 = 87. 12 m² Let, the area of steel used to make this cylindrical petrol storage tank = x m² Steel get wasted in preparation of petrol storage tank = 1/12x m² Therefore, the totalRead more

    Total surface area of cylindrical Petrol storage tank = 2πr(r + h)
    = 2 × 22/7 × 2.1 × (2.1 + 4.5) = 2 × 22/7 × 2.1 × 6.6 = 87. 12 m²
    Let, the area of steel used to make this cylindrical petrol storage tank = x m²
    Steel get wasted in preparation of petrol storage tank = 1/12x m²
    Therefore, the total steel used in cylindrical petrol storage tank = x – 1/12x = 11/12x m²
    According to the questions: 11/12x = 87.12 ⇒ x = 87.12 × 12/11 = 95.04 m²
    Hence, 95.04 m² steel is required to make this cylindrical petrol storage tank.

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