Practicing Success

Target Exam

CUET

Subject

General Test

Chapter

Quantitative Reasoning

Topic

Mensuration: 3D

Question:

A cuboid of sides 9 cm, 7 cm and 24 cm is melted to form a cube. What is the ratio of the total surface area of the cuboid to that of the cube?

Options:

18 : 17

17 : 19

19 : 18

17 : 23

Correct Answer:

19 : 18

Explanation:

Sides of a cuboid = 9 cm, 27 cm and 24 cm

Total surface area of cuboid, = 2(9 × 27 + 27 × 24 + 24 × 9) = 2(243 + 648 + 216) = 2214cm2

Volume of cuboid, = 9 × 27 × 24 = 5832 cm3.

Let, side of cube = s cm

According to problem,

= s3 = 5832

= s = 18

Side of cube = 18 cm

Total surface area of cube, = 6 × 182 = 1944

Required ratio, = 2214 ∶ 1944 = 41 ∶ 36