Question

If radius and height of a cylinder increase by 20% and15% respectively. then what is the % change in curved surface area?

Answer 1

C S A OF CYLINDER=2×22/7×R×H

NOW INCREASE IN RADIUS IS=20% and increase in HEIGHT = 15% .

LET INITIAL RADIUD=R

INCREASE IN RADIUS = R+R/5=6R/5

LET INITIAL HEIGHT =HAVE

INCREASE IN HEIGHT =H+3H/20= 23H/20

NEW CSA= 2×22/7×6R/5×23H/20

INCREASE IN CSA=2×22/7 (6/5R×23/20H-R×H)

=38%