Q15 of 227 Page 897

How many lead balls, each of radius 1 cm, can be made from a sphere of radius 8 cm?

Given,


Radius of the sphere = 8 cm


Radius of the ball we made = 1 cm


So,


Volume of sphere (when r = 1 cm) = πr3


= × 1 × 1 × 1 × π cm3


Volume of sphere (when r = 8 cm) = πr3


= × 8 × 8 × 8 × π cm3


Let the number of balls be n;


Then we have;


n × × 1 × 1 × 1 × π = × 8 × 8 × 8 × π


n = = 512


Hence, the number of lead balls can be made is 512.


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