RD Sharma - Mathematics

Book: RD Sharma - Mathematics

Chapter: 21. Surface Area and Volume of a Sphere

Subject: Mathematics - Class 9th

Q. No. 9 of CCE - Formative Assessment

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9

If a solid sphere of radius 10 cm is moulded into 8 spherical solid balls of equal radius, then the surface area of each ball (in sq. cm) is

Volume of sphere = (4/3)πr3


Given, solid sphere of radius 10 cm is moulded into 8 spherical solid balls of equal radius


(4/3)π × 103 = 8 × (4/3)π × r3


r= 10/2 = 5cm


Surface area of a sphere = 4πr2


Thus, the surface area of each sphere = 4 × π × 52 = 100π

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