Mind boggling physics problemm dirving me insane!!!!!!!!! help plz?

Question

A spherical balloon is partially blown up and its surface area is measured. More air is then added, increasing the volume of the balloon. If the surface area of the balloon expands by a factor of 7.6 during this procedure, by what factor does the radius of the balloon change?

I owe my life to whoever can help me with this... plz plz plz

Answer 1

surface area s = 4 pi r squared

so s(2) = 4 pi r (2) squared = 7.6 x s(1) = 7.6 x 4 pi r(1) squared

simplifying =>

r(2) squared = 7.6 x r (1) squared

so r (2) = r (1) x the square root of 7.6

r (2) = 2.75681 x r(1)