Susan purchased a prepaid phone card for $ 20 . Long distance calls cost 23 cents a minute using this card. Susan used her card only once to make a long distance call. If the remaining credit on her card is $ 13.79 , how many minutes did her call last?

Respuesta :

27 minutes long  because 23 multiplied by  27 is 621 and 20 subtracted by 13.79 is 6.21 and u have to find how much cents add up to that