Calculate the volume of a 0.200 solution that will completely neutralize 40.0 of a 0.264 solution. Where do I begin with this problem?

Answer 1

First you add units. Is that 0.200 M or some other unit? Second, you must know if this is a 1:1 reaction or not.
If M and if 1:1 acid/ base ratios, then
mL acid x M acid = mL base x M base.