help what is Mt?

Question

The volume Vr

 (in cubic meters) of a spherical balloon with radius r

 meters is given by =Vr43πr3

.

The radius 

Wt

 (in meters) after t

 seconds is given by =Wt+8t3

.Write a formula for the volume 

Mt

 (in cubic meters) of the balloon after t

 seconds.It is not necessary to simplify.

=Mt

Answer 1

V(r) = (4/3)pi(r^3)

where V= volume

r= radius

pi = about 3.141593

if the radius = W(t) = 8t^3

then V(t) = (4/3)pi(8t^3)^3

= (4/3)pi(8^3)(t^9)

= (2048/3)pi(t^9)