of a radio show. Each commercial is either 30 seconds or 60 seconds long. If the total comercial time during 1 hour is 13 min, how many 30-second commercials were played that hour? How many 60-second commercials?
I think you've omitted some vital information. The number of 60-second commercials could be anywhere between 0 and 13. Thirty-second commercials between 0 and 26.
