(a)
> VOL := 15 + (3-1)*t;
> Tfull := solve( VOL = 30, { t } );
>
Yes, the tank is full after 7.5 minutes.
![[Maple Math]](images/exam1-soln10.gif){kind=small}
![[Maple Math]](images/exam1-soln11.gif){kind=small}