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Question
Assuming the earth to be a sphere of radius 6370 km, how many square kilo metres is area
of the land, if three-fourth of the earth’s surface is covered by water?
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Solution
`3^(th) /4`of earth surface is covered by water
∴ `1^(th)/4` earth surface is covered by land
∴ Surface area covered by land `- 1/4 × 4πr^2`
`- 1/4 × 4 × 22/7× 6370^2`
- `127527.4km^2`
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