Question

The radius of a sphere increases by 25%. Find the percentage increase in itssurface area​

Answer 1

Answer:

156.25%

Step-by-step explanation:

formula used--->

---------------------------------

surface area = 4π r^2

now

let radius of sphere be r and intial surface area of sphere be s

S =4πr^2

now

% increase in radius=25%

25

new radius=r + r ×----------

100

1

= r + r ×-------

4

4r + r 5r

= --------------- = ---------

4 4

5r

new surface area= 4π(---------)^2

4

25 r^2

=4π ----------

16

25

= -------- (4πr^2)

16

25

= -----------(S)

16

%increase in surface area

( 25/16)s

=-------------------× 100

s

25

=--------×100=156.25%

16