Maths · Determining areas of the regions bounded by simple curves in standard forms

Three solid cubes of sides and respectively are melted to form a new cube. Find

Three solid cubes of sides \( 1 \mathrm{cm}, 6 \mathrm{cm} \) and \( 8 \mathrm{cm} \) respectively are melted to form a new cube. Find the surface area of the cube so formed.

  • A. 520 sq. \( \mathrm{cm} \)
  • B. 486 sq. \( \mathrm{cm} \)
  • C. 289 sq. \( \mathrm{cm} \)
  • D. 300 sq. \( \mathrm{cm} \)

Step-by-step solution

Total volume = 1^3 + 6^3 + 8^3 = 1 + 216 + 512 = 729 cubic cm. Side of new cube = cube root of 729 = 9 cm. Surface area = 6 * 9^2 = 6 * 81 = 486 sq. cm.
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