The calculated distance (air line) between Hersin-Coupigny and Saint-Quentin-en-Yvelines is approximately 119 miles respectively 192 kilometers.
By car or train, the actual journey to Saint-Quentin-en-Yvelines is certainly longer, as only the direct route (as the crow flies) between Hersin-Coupigny and Saint-Quentin-en-Yvelines has been calculated here.
Air line (approximately)
192 kilometers
104 nautical miles