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Question
A spherical ball of diameter 21 cm is melted and recast into cubes, each of side 1 cm. Find the number of cubes so formed.
Solution
Diameter of the spherical ball= 21 cm
Radius of the ball `=21/2 "cm"`
`4/3pir^3 = 4/3xx22/7xx21/2xx21/2xx21/2 = 11xx21xx21=4851 "cm"^3`
Volume of each cube` = 1^3 = 1 "cm"^3`
`"Number of cubes" = "Volume of spherical ball"/"Volume of each cube" = 4851/1 =4851`
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- Assertion (A) is true and Reason (R) is false.
- Assertion (A) is false and Reason (R) is true.
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