document.write( "Question 1180052: The half-life of the substance is 10 years. If we begin with 20 g of the substance, how much will be left after 5 years? \n" ); document.write( "
Algebra.Com's Answer #809671 by ikleyn(52814)\"\" \"About 
You can put this solution on YOUR website!
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\n" ); document.write( "\n" ); document.write( "            It is a good question to check if a person knows the subject.\r
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\n" ); document.write( "\n" ); document.write( "            @mananth gave you INCORRECT answer, so he definitely did not pass the test.\r
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\n" ); document.write( "\n" ); document.write( "            See my correct solution below.\r
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document.write( "Since we are given that the half-life is of 10 years, we can write the decay equation in this form\r\n" );
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document.write( "    m(t) = \"20%2A%281%2F2%29%5E%28t%2F10%29\",\r\n" );
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document.write( "where t is the time in years; m(t) is the remaining mass; 20 is the starting mass of 20 grams.\r\n" );
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document.write( "To answer the problem's question, substitute t = 5 into the formula.  Yoiu will get\r\n" );
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document.write( "    m(5) = \"20%2A%281%2F2%29%5E%285%2F10%29\" = \"20%2A%281%2F2%29%5E%281%2F2%29\" = \"20%2Fsqrt%282%29\" = \"%2820%2Asqrt%282%29%29%2F2\" = \"10%2Asqrt%282%29\" = 10*1.414.. = 14.14 grams  (rounded).\r\n" );
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document.write( "ANSWER.  14.14 grams remained after 5 years.\r\n" );
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\n" ); document.write( "\n" ); document.write( "Solved     (correctly).\r
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\n" ); document.write( "\n" ); document.write( "Again,  if a person does not know the subject firmly or is in hurry to answer the question,\r
\n" ); document.write( "\n" ); document.write( "he  (or she)  can easily make a  FATAL  MISTAKE  answering such question.\r
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\n" ); document.write( "\n" ); document.write( "A dose of accuracy and expert knowledge is required . . . \r
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\n" ); document.write( "\n" ); document.write( "On radioactive decay,  see the lesson\r
\n" ); document.write( "\n" ); document.write( "    - Radioactive decay problems \r
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\n" ); document.write( "\n" ); document.write( "You will find many similar  (and different)  solved problems there.\r
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\n" ); document.write( "\n" ); document.write( "        Use this lesson as your handbook,  textbook,  guide,  tutorials, and  (free of charge)  home teacher.\r
\n" ); document.write( "\n" ); document.write( "        Learn the subject from there once and for all.\r
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\n" ); document.write( "\n" ); document.write( "Also,  you have this free of charge online textbook in  ALGEBRA-I  in this site\r
\n" ); document.write( "\n" ); document.write( "    - ALGEBRA-I - YOUR ONLINE TEXTBOOK.\r
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\n" ); document.write( "\n" ); document.write( "The referred lesson is the part of this online textbook under the topic \"Logarithms\".\r
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\n" ); document.write( "\n" ); document.write( "Save the link to this online textbook together with its description\r
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\n" ); document.write( "\n" ); document.write( "Free of charge online textbook in ALGEBRA-I
\n" ); document.write( "https://www.algebra.com/algebra/homework/quadratic/lessons/ALGEBRA-I-YOUR-ONLINE-TEXTBOOK.lesson\r
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\n" ); document.write( "\n" ); document.write( "to your archive and use it when it is needed.\r
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