how many mL of a .25 M HCL would be required to neutralize completely 30mL of a .2 M Ca(OH)2

can anyone give a more detailed explanation?

No. Do you have any questions over what I gave you? It was the most standard titration equation.

You can do it also by writing the balanced equation, and looking for it by using mole relationships.

I will be happy to critique your work.