The calculated distance (air line) between Gumi and Yangp'yŏng is approximately 106 miles respectively 171 kilometers.
By car or train, the actual journey to Yangp'yŏng is certainly longer, as only the direct route (as the crow flies) between Gumi and Yangp'yŏng has been calculated here.
Air line (approximately)
171 kilometers
92 nautical miles