Question

4. The radius of a spherical balloon increases from 7 cm
to 14 cm as air is being pumped into it. Find the ratio
of surface areas of the balloon in the two cases.

(FULL EXPLANATION)​

Answer 1

Answer:

1cm

Step-by-step explanation:

14-7=7 7÷7=1 ok my answer is done better

Answer 2

Question :-

 ⇒  The radius of a spherical balloon increases from 7 cm

      to 14 cm as air is being pumped into it. Find the ratio

      of surface areas of the balloon in the two cases.

Given :-

  → Let the radius of balloon before air being pumped be r₁

     and after air being pumped be r₂

   → r₁ = 7cm

   → r₂ = 14 cm

To Find :-

  →  The ratio  of surface areas of the balloon in the two cases.

Solution :-

 

 → Initial surface area ( r₁ = 7 ) = 4πr²

    $4 \times \frac{22}{7} \times 7 \times 7$

   = 616 cm²

 → Surface Area = ( r₂ = 14 ) =   4πr²

   $4 \times \frac{22}{7} \times 14 \times 14$

    = 2464 cm²

  → Ratio of Surface Area

   =   $\frac{616}{2464} = \frac{1}{4}$

   $\huge{\orange{\boxed{\boxed {\boxed{\purple{\underline{\underline{\red{\mathfrak{ Ratio = \frac{1}{4} }}}}}}}}}}$