Quantitative Aptitude Ques 975
Question: The height of a circular cylinder is increased six times and the base area is decreased to one-ninth of its value. The factor by which the lateral surface area of the cylinder increases, is
Options:
A) $ 2 $
B) $ \frac{1}{2} $
C) $ \frac{2}{5} $
D) $ \frac{3}{2} $
Show Answer
Answer:
Correct Answer: A
Solution:
- Curved surface area of cylinder $ =2\pi rh $ New height = 6h Now, base area is decreased by 9 times.
$ \therefore $ Radius will be decreased by 3 times. New radius $ =\frac{1}{3}r $ Curved surface area $ =2\pi \frac{1}{3}r\times 6h=(2\pi rh)\times 2 $ Hence, lateral surface area is increased by 2 times.
BETA
