Assuming everything is metric and allowing for typos:
18,000kg aircraft, c.g. at 6.6m : moment 18000*6.6=118800kg-m
1000kg equip (assumed at 15m) : 15000kg-m moment
100kg pilot (assumed at -0.5m) : -50kg-m
90kg FO (at -0.5m) : -45 kg-m
80 kg FE (at +0.5m) : 40 kg-m
Total moment: 118800+15000-50-45+40=133745kg-m
Total mass: 18000+1000+100+90+80=19270kg
Therefore c.g. at 133745/19270=6.94m
20% mac is 6.6m so c.g. is 0.34 m aft of that
0.34m/3m (mac) is 11.3%
So c.g. is at 20% + 11.3% = 31.3%
I can't get 9.3% out of those numbers.