Okay, so my workings (again, can't promise this is right!):
25cm3 = 0.025dm3
mol of NaOH = concentration X volume = 0.102 x 0.025 = 2.55x10-3 (0.00255)
therefore mol of citric acid = 2.55x10-3 divided by 3 (as the ratio of NaOH to citric acid is 3:1) = 8.5x10-4
mean titre of citric acid = (12.10 + 12.15 + 12.15) / 3 = 12.13cm3
12.13/1000 = 0.01213 dm3 of citric acid
concentration = mol/vol, therefore conc of citric acid = 8.5x10-4 / 0.01213 = 0.070mol.dm3
No clue if that's the right answer, but that's what I got!