Better. Would you like some music?
one another. Each other applies to two persons or things; one another to more than two.
per. Per should be followed by a Latin word.
Wrong. His salary is $5,000 per year.
Right. His salary is $5,000 a year.
Right. His salary is $5,000 per annum.
Use according to or in accordance with instead of as per.
Wrong. He paid me Monday as per our agreement.
Right. He paid me Monday in accordance with our agreement.
per cent.