Sal and Jen went to the store together, and each bought the same car stereo. Sal used a card to make the purchase, and the full amount was immediately withdrawn from his bank account. Jen used a card to make the purchase, and she received a bill within 15 days of the purchase. She paid 21 point 3 0 dollars for the next 18 months until the bill was paid in full. The full payment included 58 point 6 0 dollars in interest. Which statement describes Sal’s purchase?