A well has to be dug out 20 m deep and i

CUET Preparation Today

Start Free Mocks

Home Questions 8M3GD9SSXS

Target Exam

CUET

Subject

General Test

Chapter

Quantitative Reasoning

Topic

Mensuration: 3D

Question:

A well has to be dug out 20 m deep and its radius is 3.5 m. Find the cost of plastering the inner curved surface at ₹5 per square meter.

Options:

₹750

₹2,200

₹1,000

₹1,750

Correct Answer:

₹2,200

Explanation:

The inner curved surface area of the well = 2πrh

= 2 × 22/7 × 3.5 m × 20 m

= 440 m²

The cost of plastering the inner curved surface at ₹5 per square meter = 440 × 5 = ₹2,200