SSC MTS 2023 PYQ — Question 9

SSC MTS - 08 May 2023 - Shift 1 • Quantitative Aptitude • Q9

A cuboid whose sides are 8 cm, 27 cm, and 64 cm is melted to form a new cube. What is the respective ratio of the total surface area of the cuboid and cube?

Show answer & explanation

Correct answer: D

Explanation

The correct answer is option 4 i.e. 307 : 216.

The volume of the cuboid is = l × b × h

⇒ 8 × 27 × 64 = 13824 cm3

The volume of the cube will be equal to the volume of the cuboid.

Hence¸

⇒ s3 = 13824

⇒ s = 313824^3\sqrt{13824}

⇒ s = 24 cm

The ratio of the total surface area of the cuboid and cube:

⇒ 2(l × b + b × h + h × l) : 6 × s2  

⇒ 2(8 × 27 + 27 × 64 + 64 × 8) : 6 × 242 = 2 × 2456  : 6 × 576

⇒ 4912 cm2  :  3456 cm2

⇒ 307 : 216