The radius and height of a solid cylinder are increased by 2% each. What will be the approximate percentage increase in volume?
Show answer & explanation
Correct answer: C
Explanation
The correct answer is option 3 i.e. 6.12
Let radius and height be 100 cm and 100 cm respectively
Volume of cylinder = π × 1002 × 100 = π × 1003
After 2% increase in height and radius
h = 102, r = 102
New volume = π × 1022 × 102
% increase =( π × 1022 × 102 - π × 1003)/π × 1003 = 6.12%
Alternative method :
Ratio of volume of two cylinders depends on r2h
Let the radius and height be 10
Required ratio = 1000 : 1061.208
Required percentage = ((1061.208 - 1000)/1000) × 100
= 6.12 %