Question

the diameter of a sphere balloon increases from 14cm to 28cm as air is being pumped into it . find the ratio of surface areas of the balloon in to cases.
( plz help me out quickly )

Answer 1

volume of sphere = $\frac{4}{3} \pi r^{3}$
having initial radius as $r_{1}$ and final radius as $r_{2}$,

$v_{1}:v_{2} = \frac{ \frac{4}{3} \pi r_{1}^{3} }{\frac{4}{3} \pi r_{2}^{3}}$
= $\frac{r_{1}^{3}}{r_{2}^{3}}$
= $\frac{14*14*14}{28*28*28}$
= $\frac{1}{8}$
= 1:8

Answer 2

$<marquee style="border:orange 3px solid">☺ Answer= 1:4☺</marquee>$
$<b>$
small balloon's r=7cm 
big balloon's R=14 cm 
so , 
the ratio= (4*pi*r^2)/(4*pi*R^2) 
= r^2/R^2 
= 7^2/14^2 
= 49/196 
= 1/4 
= 1:4 ans

$<b><font face=copper black size=4 color=green>$
$<marquee style="border:orange 3px solid">☺ please mark as brainliest☺</marquee>$