Correct answer is... 28 m/s It is equal to 5512 ft/min. To give an example, Eurocopter X3 with it's climb speed of 28 m/s that takes off from airfield of elevation 100 metres (300 feets) will reach flight level 100 (10,000 feets or 3 km above mean sea level) after about 2 minutes.
Disclaimer: Our articles and data connected to climb speed of Eurocopter X3 are based on public data from various sources. We are very picky to select an reliable data providers, but we cannot guarantee that everything is 100% error-proof. We recommend for any serious purpose - as a rule of thumb - to request offical data about climb speed from manufacturer of Eurocopter X3.