Question

the radius of the sphere is 5 CM. if the radius be increased by 20 % ,find by how much percent the volume is increased

Answer 1

RADIUS OF SPHERE= 5 CM
INCREASE IN RADIUS= 20%
RADIUS INCREASED= 5× 1/5
= 1 CM
NEW RADIUS= 6 CM
VOLUME= π( 5)^ 2 H
NEW VOLUME= π( 6)^ 2 H
CHANGE IN VOLUME= π( 6)^ 2 H-π( 5)^ 2 H
= 11π H
CHANGE IN% ={ 11π H/π (5)^2 H}× 100
= 44%

HOPE IT HELP YOU

Answer 2

$\frac{20}{100} \times 5 = 1 \\ r2 = 6 \\ \frac{v1}{v2} = \frac{ \frac{4}{3} \pi {r1}^{3} }{ \frac{4}{3}\pi {r2}^{3} } \\ = \frac{ {r1}^{3} }{ {r2}^{2} } \\ = \frac{ {5}^{3} }{ {6}^{3} } \\ = \frac{125}{216}$