Target Exam

CUET

Subject

General Test

Chapter

Quantitative Reasoning

Topic

Mensuration: 3D

Question:

A solid metallic sphere of radius 6.3 cm is melted and recast into a right circular cone of height 25.2 cm. What is the ratio of the diameter of the base to the height of the cone?

Options:

2 : 3

3 : 2

2 : 1

1 : 2

Correct Answer:

1 : 2

Explanation:

We know that,

Volume of sphere = \(\frac{4}{3}\)πR

Volume of cone = \(\frac{1}{3}\)πr2h

We have,

Radius of the sphere = 6.3 cm

Height of the cone = 25.2 cm

According to the question,

\(\frac{4}{3}\)πR3 = \(\frac{1}{3}\)πr2h

\(\frac{4}{3}\)× 6.3 × 6.3 × 6.3 = \(\frac{1}{3}\) × r2 × 25.2

on solving further,

r = 6.3

Diameter = 2 × 6.3 = 12.6

Required ratio = 12.6 : 25.2 = 1 : 2