4 Views

Question : Which of the following statements is not correct?

Option 1: For a given radius and height, a right circular cone has a lesser volume than a right circular cylinder.

Option 2: If the side of a cube is increased by 10%, the volume will increase by 33.1%.

Option 3: If the radius of a sphere is increased by 20%, the surface area will increase by 40%.

Option 4: Cutting a sphere into 2 parts does not change the total volume.


Team Careers360 12th Jan, 2024
Answer (1)
Team Careers360 18th Jan, 2024

Correct Answer: If the radius of a sphere is increased by 20%, the surface area will increase by 40%.


Solution : Let the radius of the original sphere = $r$
So, the surface area of the original sphere = $4\pi r^2$
Radius of sphere after 20% increase = $r+\frac{20}{100} =1.2r$
Surface area of new sphere = $4\pi (1.2r^2) = 4\pi r^2 \times 1.44$
Percentage increase in area = $\frac{1.44-1}{1}\times 100 $ = 44%
Hence, the correct answer is "If the radius of a sphere is increased by 20%, the surface area will increase by 40%".

Know More About

Related Questions

TOEFL ® Registrations 2024
Apply
Accepted by more than 11,000 universities in over 150 countries worldwide
Manipal Online M.Com Admissions
Apply
Apply for Online M.Com from Manipal University
View All Application Forms

Download the Careers360 App on your Android phone

Regular exam updates, QnA, Predictors, College Applications & E-books now on your Mobile

150M+ Students
30,000+ Colleges
500+ Exams
1500+ E-books