Please assist, I'm really bad with word problems

The surface area of the balloon is

Step-by-step explanation:

Given;

S(r) = 4πr²

where;

S is the surface area of the balloon

r is the radius of the surface

The radius of the balloon at time "t" is given as;

The surface area of the balloon as a function of time "t" is calculated as;

hiking down a winding trail.

step-by-step explanation:

the answer is ! ?