मराठी

The difference between the outer and inner curved surface area of a hollow cylinder is 264 cm2. If its height is 14 cm and the volume of the material in it is 1980 cm3, find its total surface area. - Mathematics

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प्रश्न

The difference between the outer and inner curved surface area of a hollow cylinder is 264 cm2. If its height is 14 cm and the volume of the material in it is 1980 cm3, find its total surface area.

बेरीज

उत्तर

Curved surface area of cylinder = πr2h
Height h = 14cm
The difference between the outer and inner curved surface area = 264cm2
2π x {(Router)-(Rin)} x h = 264cm2
⇒ π x {(Router)-(Rin)} x h = 132     ...(1)
Volume of material in cylinder = 1980cm3
π{(Router)2-(Rin)2} x h = 1980
π{(Rouer)-(Rin){(Router+(Rin)} x h = 1980   ...(2)
Substituting (1) in (2), we get
{(Router+(Rin)} x 132 = 1980
∴ {(Router+Rin)} = 15cm
Total surface area of a hollow cylinder
= 2π{(Router+Rin)} x h + 2π{(Router)2-(Rin)2}

= `2pi xx 15 xx 14 + 2 xx (1980)/(14)`
= 1602cm2
∴ The total surface area of the hollow cylinder is 1602cm2.

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  या प्रश्नात किंवा उत्तरात काही त्रुटी आहे का?
पाठ 25: Surface Areas and Volume of Solids - Exercise 25.2

APPEARS IN

फ्रँक Mathematics [English] Class 9 ICSE
पाठ 25 Surface Areas and Volume of Solids
Exercise 25.2 | Q 29

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