document.write( "Question 825967: A total of 1200 students attend a top high school. The ratio of teachers to students is 1:30. How many teachers are there at the school?\r
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Algebra.Com's Answer #497847 by math-vortex(648)\"\" \"About 
You can put this solution on YOUR website!
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document.write( "Hi, there--\r\n" );
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document.write( "THE PROBLEM:\r\n" );
document.write( "a) A total of 1200 students attend a top high school.  The ratio of teachers to students is 1:30. \r\n" );
document.write( "How many teachers are there at the school?\r\n" );
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document.write( "b) Two-fifth of the students own personal computers.  How many students do not own Personal computers?  \r\n" );
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document.write( "c) Thirty percent of the students who own personal computer also own play stations. What \r\n" );
document.write( "fraction of the students in the school own play station?\r\n" );
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document.write( "A SOLUTION:\r\n" );
document.write( "a) A total of 1200 students attend a top high school.  The ratio of teachers to students is 1:30. \r\n" );
document.write( "How many teachers are there at the school?\r\n" );
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document.write( "We can use the ratio of teachers to students to determine the the number of teachers in the \r\n" );
document.write( "school. There are several ways to set up a proportion, depending upon what you compare. \r\n" );
document.write( "Here is one way.\r\n" );
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document.write( "Let T be the number of teachers.\r\n" );
document.write( "Let S be the number of students.\r\n" );
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document.write( "The most challenging part of these problems can be setting up a valid proportion. I like to\r\n" );
document.write( "say the proportion aloud and listen for the matching pattern: \r\n" );
document.write( "\"Teachers\" is to \"Students\" as 1 is to 30\r\n" );
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document.write( "The proportion is T : S = 1 : 30 or \"T%2FS=1%2F30\".\r\n" );
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document.write( "We know that we have 1200 students so we substitute 1200 for S in the proportion.\r\n" );
document.write( "\"T%2F1200=1%2F30\"\r\n" );
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document.write( "Solve for T.\r\n" );
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document.write( "If the denominators on both sides of the equation are the same, it will be easy to see the \r\n" );
document.write( "value of T. Notice that 30*40=1200, so we multiply the right side of the proportion by 40/40.\r\n" );
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document.write( "\"T%2F1200=%281%2F30%29%2A%2840%2F40%29\"\r\n" );
document.write( "\"T%2F1200=40%2F1200\"\r\n" );
document.write( "\"T=40\"\r\n" );
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document.write( "There are 30 teachers at the high school.\r\n" );
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document.write( "b) Two-fifth of the students own personal computers.  How many students do not own \r\n" );
document.write( "Personal computers?  \r\n" );
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document.write( "We know that we have 1200 students. To solve the problem 2/5 of 1200, we multiply \r\n" );
document.write( "(2/5)*(1200).\r\n" );
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document.write( "Multiply 2*1200, then divide the result by 5.\r\n" );
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document.write( "2*1200 = 2400\r\n" );
document.write( "2400/5 = 480\r\n" );
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document.write( "480 students own personal computers. We want to know how many students do NOT \r\n" );
document.write( "own PCs, so we subtract 1200-480=720.\r\n" );
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document.write( "720 students do not own PCs.\r\n" );
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document.write( "c) Thirty percent of the students who own personal computer also own play stations.  What \r\n" );
document.write( "fraction of the students in the school own play station?\r\n" );
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document.write( "We know that 480 students own personal computers. Since 30% of them also own play\r\n" );
document.write( "stations, we want to find 30% of 480. \r\n" );
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document.write( "When you multiply a percent, you need to convert it to the decimal equivalent. 30% means\r\n" );
document.write( "30 out of 100 or 30 hundredths or 0.30. Now multiply 0.30 * 480.\r\n" );
document.write( "0.30 * 480  = 144.\r\n" );
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document.write( "144 students own a personal computer and a playstation.\r\n" );
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document.write( "If you need multiplying decimals, here is a good link:\r\n" );
document.write( "http://www.mathsisfun.com/multiplying-decimals.html\r\n" );
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document.write( "Hope this helps! Feel free to email if you have any questions about the solution.\r\n" );
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document.write( "Good luck with your math,\r\n" );
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document.write( "Mrs. F\r\n" );
document.write( "math.in.the.vortex@gmail.com\r\n" );
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