document.write( "Question 921445: Find the LCM and HCF of 330 and 450. Buzzer A is programmed to beep every 330 seconds, while buzzer B is set for every 450 seconds. Buzzer A and B buzz together for the first time at 1.00pm. At what time is their sound heard together again? \n" ); document.write( "
Algebra.Com's Answer #565016 by Edwin McCravy(20081)\"\" \"About 
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document.write( "330 and 450.\r\n" );
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document.write( "We prime factor 330\r\n" );
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document.write( "330 = 2*165 = 2*3*55 = 2*3*5*11\r\n" );
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document.write( "We prime factor 450\r\n" );
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document.write( "450 = 2*225 = 2*3*75 = 2*3*3*25 = 2*3*3*5*5\r\n" );
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document.write( "Line the prime factors up in columns of like factors like this:\r\n" );
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document.write( "330 = 2*3* *5* *11\r\n" );
document.write( "450 = 2*3*3*5*5\r\n" );
document.write( "------------------\r\n" );
document.write( "HCF = 2*3  *5      = 30  <-- bring down only the factors that are on both lines\r\n" );
document.write( "                             and multiply them.  \r\n" );
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document.write( "330 = 2*3* *5* *11\r\n" );
document.write( "450 = 2*3*3*5*5\r\n" );
document.write( "------------------\r\n" );
document.write( "LCM = 2*3*3*5*5*11 = 4950  <-- bring down all the factors that are on either\r\n" );
document.write( "                               line and multiply them.\r\n" );
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document.write( "Both will buzz together in 4950 seconds. Divide by 60. Get 82.5 minutes.\r\n" );
document.write( "Divide by 60 again. Get 1.375 hours.  The decimal part, 0.375 times 60 \r\n" );
document.write( "is 22.5 minutes.  So they'll buzz together in 1 hour and 22 and a half \r\n" );
document.write( "minutes after 1:00pm. That's 2:22:30pm.\r\n" );
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document.write( "Edwin

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