how many mL of 1M HC2H3O2 are required to neutralize a spill of 25mL of 6M NaOH?

1 mole of acetic acid reacts with 1 mole of NaOH to create sodium acetate and water.

So volume V in mL required:
V mL * 1M = 25 mL * 6M
Solve for V