document.write( "Question 1101681: ishita invested a sum of Rs 12000 at 5 percent per annum interest. She received an amount of Rs 13230 after n years. find the value of n.
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Algebra.Com's Answer #716285 by Theo(13342)\"\" \"About 
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formula is f = p * (1+r)^n\r
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\n" ); document.write( "\n" ); document.write( "f is the future value
\n" ); document.write( "p is the present value
\n" ); document.write( "r is the interest rate per time period
\n" ); document.write( "n is the number of time periods.\r
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\n" ); document.write( "\n" ); document.write( "in your problem:\r
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\n" ); document.write( "\n" ); document.write( "f = 13230
\n" ); document.write( "p = 12000
\n" ); document.write( "r = .05
\n" ); document.write( "n = what you want to find.\r
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\n" ); document.write( "\n" ); document.write( "the formula becomes 13230 = 12000 * (1.05)^n\r
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\n" ); document.write( "\n" ); document.write( "divide both sides of the equation by 12000 to get:
\n" ); document.write( "13230/12000 = 1.05^n
\n" ); document.write( "take the log of both sides of the equation to get:
\n" ); document.write( "log(13230/12000) = log(1.05^n)
\n" ); document.write( "since log(1.05^n) is equal to n * log(1.05), your equation becomes:
\n" ); document.write( "log(13230/12000) = n*log(1.05)
\n" ); document.write( "divide both sides of the equation by log(1.05) to get:
\n" ); document.write( "log(13230/12000) / log(1.05) = n
\n" ); document.write( "solve for n to get:
\n" ); document.write( "n = 2\r
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\n" ); document.write( "\n" ); document.write( "the money will grow from 12000 to 13230 in 2 years at 5% interest per year.\r
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\n" ); document.write( "\n" ); document.write( "12000 * 1.05^2 = 13230\r
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