The sum of the exterior angles of a regular polygon = 360°.

\(\therefore x + (x + 5) + (x + 10) + (x + 15) + (x + 20) = 360°\)

\(5x + 50 = 360° \implies 5x = 360° - 50° = 310°\)

\(x = \frac{310°}{5} = 62°\)