Answer
$$\frac{5\pi}{3} \space radians$$
Work Step by Step
Multiply by $\dfrac{\pi\space \text{radians}}{180^\circ}$ to convert from degrees to radians:
$$300^\circ \times \dfrac{\pi\space \text{radians}}{180^\circ}= \dfrac{5\pi}{3} \space \text{radians}$$
