<PRE><B>Question 1001612</B>
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T=number of 30 second commercials; S=number of 60 second commercials
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T+S=27
T=27-S
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17 min x 60 sec/min=1020 seconds
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30T+60S=1020
30(27-S)+60S=1020
810-30S+60S=1020
30S=210
S=7
ANSWER 1: There were seven 60 second commercials.
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T=27-S=27-7=20
ANSWER 2: There were twenty 30 second commercials.
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CHECK:
30T+60S=1020
30(20)+60(7)=1020
600+420=1020
1020=1020
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