What is the pH of a solutiont that is .1 M HCl (strong acid)?

( And a few more questions if you can answer these too:] )

What is the pH of a solution that has a pOH of 11?

What is the molarity, or concentration, of [H3O+] of a solution at pH 5?

(step by step answers would be ideal, thanks!)
3 answers 3