The calculated distance (air line) between West Jerusalem and Rishon LeTsiyyon is approximately 28 miles respectively 46 kilometers.
By car or train, the actual journey to Rishon LeTsiyyon is certainly longer, as only the direct route (as the crow flies) between West Jerusalem and Rishon LeTsiyyon has been calculated here.
Air line (approximately)
46 kilometers
25 nautical miles