a disc jockey must play 14 commercial spots during 1 hour of a radio show. each commercial is either 30 seconds or 60 seconds long. if the total commercial time during 1 hour is 11 min, how many 30 seconds commercials were played that hour. how many 60 second commercials?

1 answer

Let x = # 30 second commercials.
let y = # 60 second commercials.
Two equations can be written.
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30x + 60y = 11*60
x + y = 14
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Solve for x and y.
Post your work if you get stuck.