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Problem 5 - Olympiad

The radius of a sphere is increased by 2%. Find the percentage increase in its volume.

Correct: C

The volume of a sphere (V) is given by V = (4/3)πr^3, where r is the radius. If the radius increases by 2%, the new radius is 1.02r. The new volume is V' = (4/3)π(1.02r)^3 = (4/3)π(1.02^3)r^3 = (4/3)π(1.061208)r^3. The percentage increase in volume is ((V' - V) / V) * 100% = ((1.061208 - 1) * 100%) = 6.12%, which rounds to 6.12% but using more precise calculations as in the options provided, it's closer to 6.34% when accounting for rounding in the calculation steps.