If a solid sphere of radius 10 cms is moulded into 8 spherical solid balls of equal radius, then surface area of each ball (in cm2) is________?
Correct answer: A. 100π
- A. 100π
- B. 7π
- C. 60π
- D. 50π
Explanation
Eight equal balls have one-eighth of the original sphere's volume, so each ball has radius 10 cm ÷ 2 = 5 cm because volume scales with the cube of radius. Its surface area is 4π(5 cm)² = 100π cm². The likely wrong choice is 60π cm², which does not correctly use the new radius or the sphere surface-area formula.
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Area measures the surface enclosed by two-dimensional figures, while volume measures the space occupied by three-dimensional solids. Problems use formulas for rectangles, triangles, circles, prisms, cylinders, cones, spheres, and composite figures, including unit conversion and the distinction between surface area, lateral area, and volume.
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