Does unit matter?
As long as volume units are consistent (e.g., both mL or both L), the calculation works.
This calculation assumes a 1:1 mole ratio (e.g., HCl + NaOH). At the equivalence point, Moles Acid = Moles Base.
0.1 M x 25 mL = 0.1250 M x 20 mL
The base is more concentrated than the acid, so a smaller volume of base is needed to neutralize the acid.
In a lab titration, you would use an indicator (like phenolphthalein) that changes color exactly when the neutralization is complete to measure these volumes accurately.
MaVa = MbVbMaMolarity of AcidVaVolume of AcidMbMolarity of BaseVbVolume of Base