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Question
Find the volume of a sphere, if its surface area is 154 sq.cm.
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Solution
Let the radius of the sphere be r cm.
Surface area of the sphere = 154 cm2
∴ 4πr2 = 154 cm2
⇒ `4 xx 22/7 xx r^2` = 154
⇒ r2 = `[154 xx 7]/88`
⇒ r2 = 12.25
⇒ r2 = (3. 5)2
⇒ r = 3. 5
∴ Volume of the sphere = `4/3 πr^3`
= `4/3 xx 22/7 xx (3. 5)^3`
= 179.67 cm3
Thus, the volume of the sphere is 179.67 cm3.
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