We're told 100 kg must be moved from Station ("STN") 030 to STN 120, with a CG presently at STN 115.8. Aircraft mass is 4750 kg.

What will the new CG be?
Look at your M&B notes, "Body Stations" - we'll take the formula (memorise it!):
Δ Mass...............Δ CG
---------- = ----------------
Total mass........distance moved
Viz,
100 kg ...............Δ CG
---------- = ----------------
4750 kg..............(120-30)
becomes,
0.021 * 90 = 1.89
Original CG was at STN 115.8, so the new CG is STN 117.69. A rearward movement of mass, so a rearward movement of the CG.