How much water do you need to add to 10 mL of a solution of HCl with a pH of 3 to change the pH to 6?

Answer 1

pH = 3, (H^+) = 1E-3
pH = 6, (H^+) = 1E-6

So how much dilution is required?
1 x 10E-3*(10 mL/X mL) = 1E-6
Solve for X. I get something like 10,000 mL so you would need to add 10,000-10 = ??