document.write( "Question 895830: the traffic light at three different road crossings change after every 48,72 and 108 sec,.if they all change simultaneously at 8:20:00 hrs, then at what time will they again change simultaneously? \n" ); document.write( "

Algebra.Com's Answer #543052 by Fombitz(32388) $\"\"$ $\"About$

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Find the LCM of 48, 72, and 108.
\n" ); document.write( " $\"48=2%2A2%2A2%2A2%2A3=2%5E4%2A3\"$
\n" ); document.write( " $\"72=2%2A2%2A2%2A3%5E2=2%5E3%2A3%5E2\"$
\n" ); document.write( " $\"108=2%2A2%2A3%2A3%2A3=2%5E2%2A3%5E3\"$
\n" ); document.write( "So then,
\n" ); document.write( " $\"LCM=2%5E4%2A3%5E3=16%2A27=432\"$
\n" ); document.write( "So count 432 seconds from 8:20.
\n" ); document.write( "432 seconds equals 7 minutes 12 seconds.
\n" ); document.write( "8:20:00 + 0:07:12=8:27:12 \n" ); document.write( "

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