Question : The radius of a circle is increased by 10%. The percentage increase in its area is:
Option 1: 10%
Option 2: 11%
Option 3: 20%
Option 4: 21%
New: SSC MTS Tier 1 Answer key 2024 out
Don't Miss: Month-wise Current Affairs | Upcoming Government Exams
New: Unlock 10% OFF on PTE Academic. Use Code: 'C360SPL10'
Correct Answer: 21%
Solution : Given: The radius of a circle is increased by 10%. Let the radius be r units, then area = $\pi r^2$ sq. units After a 10% increase, new radius = $(r+r×\frac{10}{100})=\frac{11r}{10}$ units Now, the area = $\pi (\frac{11r}{10})^2=\frac{121\pi r^2}{100}$ sq. units Therefore, the percentage increase in area is, = $\frac{(\frac{121\pi r^2}{100}-\pi r^2)}{\pi r^2}×100$ = $(\frac{21\pi r^2}{100})×100$ = 21% Hence, the correct answer is 21%.
Application | Cutoff | Selection Process | Preparation Tips | Eligibility | Exam Pattern | Admit Card
Question : Each side of a square is increased by 10%. The percentage increase in its area is:
Option 1: 25
Option 2: 12.5
Option 3: 20
Option 4: 21
Question : A number is increased by 20% and then the increased number is decreased by 20%. The net increase or decrease is:
Option 1: Decrease 2%
Option 2: Increase 4%
Option 3: Increase 2%
Option 4: Decrease 4%
Question : The cost of an article worth Rs. 100 is increased by 10% first and again increased by 10%. The total increase (in Rs.) is:
Option 1: 20
Option 2: 21
Option 3: 110
Option 4: 121
Question : If the altitude of a triangle is increased by 10% while its area remains the same, its corresponding base will have to be decreased by:
Option 1: $10\%$
Option 2: $9\%$
Option 3: $9\frac{1}{11}\%$
Option 4: $11\frac{1}{9}\%$
Question : If each edge of a cube is increased by 40%, the percentage increase in its surface area is:
Option 1: 40%
Option 2: 60%
Option 3: 80%
Option 4: 96%
Regular exam updates, QnA, Predictors, College Applications & E-books now on your Mobile