document.write( "Question 201482: A disc jockey must play 16 commercial spots during 1 hour of a radio show. Each commercial is either 30 seconds long or 60 seconds long. If the total commercial time during 1 hour is 13 min, how many 30 second commercials were played that hour? How many 60 second commercials? \n" ); document.write( "

Algebra.Com's Answer #151704 by stanbon(75887) $\"\"$ $\"About$

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A disc jockey must play 16 commercial spots during 1 hour of a radio show. Each commercial is either 30 seconds long or 60 seconds long. If the total commercial time during 1 hour is 13 min, how many 30 second commercials were played that hour? How many 60 second commercials?
\n" ); document.write( "--------------------------------------------------
\n" ); document.write( "Quantity Equation: s + t = 16
\n" ); document.write( "time Equation: 60s + 30t = 13*60
\n" ); document.write( "----------------------------
\n" ); document.write( "Simplify
\n" ); document.write( "s + t = 16
\n" ); document.write( "2s + t = 26
\n" ); document.write( "-------------------
\n" ); document.write( "Subtract 1st from 2nd to get:
\n" ); document.write( "s = 10 (# of sixty second commercials)
\n" ); document.write( "---
\n" ); document.write( "Substitute to solve for \"t\":
\n" ); document.write( "10 + t = 16
\n" ); document.write( "t = 6 (# of thirty second commercials)
\n" ); document.write( "=============================================
\n" ); document.write( "Cheers,
\n" ); document.write( "Stan H. \n" ); document.write( "

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