Using rotational kinematic formulas

A fan initially rotates clockwise at $9.0{\displaystyle \frac{\text{rad}}{\text{s}}}$‍, but has a counterclockwise angular acceleration of $3.0{\displaystyle \frac{\text{rad}}{{\text{s}}^2}}$‍ and reaches a counterclockwise angular speed of $27{\displaystyle \frac{\text{rad}}{\text{s}}}$‍.

How much time did this change in the angular velocity take?

$\text{s}$‍