Question

*If the radius of a sphere is doubled, then what is the ratio of the old surface area to the new surface area?* 1️⃣ 1 : 2 2️⃣ 2 : 1 3️⃣ 4 : 1 4️⃣ 1 : 4

Answer 1

Answer:

4️⃣ 1:4

Step-by-step explanation:

Surface area of a sphere = 4$\pi$r²

Now if r gets doubled,

Then;

       Radius of new circle = 2r

        Surface area of new sphere formed= 4$\pi$(2r)²

                                                                    = 4$\pi$4r²

                                                                    = 16$\pi$r²

Therefore, their ratios,

 = 4$\pi$r²:16

 = 1:4