Multiple choice

If cuboid of size $(8 \times 4 \times 2):cm^3$ is melted and reshaped as cylinder of height $7$ cm, find the radius of cylinder.

  1. $\displaystyle\frac{16}{\sqrt{22}}$cm
  2. $\displaystyle\frac{8}{\sqrt{22}}$cm
  3. $\displaystyle\frac{4}{\sqrt{22}}$cm

  4. None of the above
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B Correct answer
AI explanation

The volume of the cuboid is calculated as 8 times 4 times 2, which equals 64 cubic cm. When reshaped into a cylinder, this volume remains constant, so pi times r squared times height equals 64, and using 22 over 7 for pi with a height of 7 gives r squared equals 64 over 22. Taking the square root gives the radius as 8 over the square root of 22 cm.

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