Ali and Paul walked from Town X to Town Y at 6km/h and 4 km/h respectively. Ali left Town X at 9:15am and arrived at Town y at 10:30am. When Ali arrived at Town Y, Paul was 3.1 km away from Y. What time did Paul leave Town X?

5:13am

6:18am

7:22am

9:24am

None of the above