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SSC CPO 2020 PYQ — Question 145

SSC CPO - 25 Nov 2020 - Shift 2 • Quantitative Aptitude • Q145

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If the volume of a sphere is 4851 cm3, then its surface area ( in cm2) is : ( Take π = 227\frac{22}{7})

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Correct answer: C

Explanation

The correct answer is Option 3 i.e. 1386.

We know that,

Surface area of sphere = 4 × πr2

Volume of sphere = (4/3) × πr3

here, r = Radius of sphere

Now, according to the question

Volume of sphere = (4/3) × πr3

⇒ 4851 = (4/3) × (22/7) × r3

⇒ r3 = 4851 × 21/88

⇒ r3 = 441 × 21/8

⇒ r = 21/2

Surface area of sphere = 4 x πr2

⇒ 4 × (22/7) × (21/2)2

⇒ 4 × (22/7) × (441/4)

⇒ 22 × 63 = 1386

Thus, 

The surface area of the sphere is 1386 cm2.