The radius r (in inches) and volume V of a spherical balloon are related by the function r(V)=∛(3V)/(4π^3). Since air is fed into the balloon, the volume after t seconds is given by V(t)=10+20t.

Question

1. Find the radius of the balloon 40 seconds after air is pumped into the balloon.

Answer 1

Substitute 40 into the equation for V(t).

Then plug that answer into the equation for r(V).

Is there some problem about doing those 2 steps?