a music store featured used cds on sale at three disk for 13.50,what would it cost to purchase 14 cds

Iam so stuck. what is the worked out answer for this question?

Acomputer store bought a program at a cost of $10 and sold it for $13. find the percent markup

Agrid shows the positions of a subway stop and your house. the subway stop is located at (-5,2) and your house is located at (-9,9). what is the distance, to the nearest unit, between your house and the subway stop?