we know that
speed=distance/time
Jane speed is ------> 63 km/3.5 hours------> 18 Km/hours
1 Km is equals to-------------> 1000 m
1 hour is equals to---------> 3600 sec
so
18 Km/hour------> 18*1000/3600------> 5 m/sec
for distance =30 Km
Jane s time=?
time=distance/speed------> time=30000/5----> time=6000 sec----> 100 min
the time it took Sali to reach 30 km was-----> 100 min-4 min---> 96 min
Sali speed is---> 30000/96 min--> 312.5 m/min----> 312.5/60---> 5.21 m/sec
the answer is
Jane speed is 5 m/sec
Sali speed is 5.21 m/sec