Question

An iron spherical ball of radius 21cm is melted and it is re casted in hemispherical balls of radius 7cm. How many such balls will be formed?

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Answer 1

Volume will remain constant.

Let's assume x such hemispherical balls will be formed.

So $\frac{4}{3}$ $\pi$ $r^3$ = x $\times$ $\frac{2}{3}$ $\pi$ $r^3$

$\Rightarrow$ x = 54