Question

find the ratio of total surface area of a sphere and a solid hemisphere of same radius

Answer 1

Hey mate .
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Let,

The radius of both the hemisphere and sphere be 'r'

We know,

Surface area of the sphere = $\frac{4}{3} \pi \: r {}^{3}$

And,

Surface area of the hemisphere = $\frac{2}{3} \pi \: r {}^{3}$

So, The ratio of total surface area of a sphere and a solid hemisphere of same radius

= $\frac{ \frac{4}{3}\pi \: r {}^{3} }{ \frac{2}{3} \pi \: r {}^{3} } \\ \\ = \frac{2}{1}$

= 2:1

Hope it helps !!

Answer 2

Ratio=4pie r square: 3pie r square=4:3

The required ratio is 4:3