Practicing Success

Target Exam

CUET

Subject

General Test

Chapter

Quantitative Reasoning

Topic

Mensuration: 3D

Question:

A solid metallic cube of side 9 cm and solid metallic cuboid having dimensions 5 cm, 13 cm, 31 cm are melted to form single cube. How much(in ₹) is the cost to polish the new cube at a rate of ₹10 per cm2?

Options:

8,650

27,440

13,620

11,760

Correct Answer:

11,760

Explanation:

We know that,

Volume of cube = (side)3

Volume of cuboid = length × breadth × height

Total surface area of cube = 6 × side2

We have,

Side of cube = 9 cm

Length of the Cuboid  = 5 cm, breadth = 13 cm, height = 31 cm

Volume of Solid metallic cube = (9)3 = 729 cm3

Volume of Solid metallic cuboid = 5 × 13 × 31 = 2015 cm3

Volume of single cube = Volume of Solid metallic cube + Volume of Solid metallic cuboid

= 729 + 2015 = 2744 cm3

Side of Recasted cube = (Side)3 = 2744

= side = 14 cm

Total surface area of cube = 6 × 14 × 14 = 1176 cm2