Solubility of Calcium Hydroxide

Question

At some temperature, the solubility of Ca(OH)2 is 0.0880 g/100mL.
Calculate the concentrations of the Ca2+ and OH− ions in a saturated solution of Ca(OH)2 and use these to calculate a value for Ksp of Ca(OH)2.
[Ca^2+]= 1.19 x10^-2
[OH-] = 2.38 x10^-2
Ksp= 6.70 x10^-6
I found the Ksp and concentrations already but I'm not sure how to answer the question below.
Calculate the volume of 0.0100 M HCl required to neutralize 20.00 mL of the saturated solution.

Answer 1

Assuming your calculations are correct and (OH^-) = 2.38E-2 M, that is 2.38E-2 mols/L or 2.38E-2 x 20/1000 = mols/20.00 mL
OH^- + HCl --> H2O + Cl^-
So M = mols/L or L = mols/M = mols in the 20/M HCl = ?

Answer 2

I dont quite understand the last part so I do (OH-) 2.38 E-2 x 20ml/1000ml = 4.76 x E-4 then use that info for HCl? how?