document.write( "Question 1056826: David needs $25,000 in 8 years. He currently has $15,000. At what simple interest rate must he invest to get exactly $25.000? \n" ); document.write( "
Algebra.Com's Answer #671900 by math_helper(2461)\"\" \"About 
You can put this solution on YOUR website!
The simple interest formula will suffice
\n" ); document.write( "
\n" ); document.write( " \"+F+=+P+%28+1+%2B+rt+%29+\"\r
\n" ); document.write( "\n" ); document.write( "where
\n" ); document.write( " F = future value of investment
\n" ); document.write( " P = present value of investment
\n" ); document.write( " r = interest rate
\n" ); document.write( " t = number of periods\r
\n" ); document.write( "\n" ); document.write( " In this problem F=25000, t=8yrs, and P=15000. The problem asks us to find the rate r.\r
\n" ); document.write( "\n" ); document.write( " 25000 = 15000(1 + r*8)
\n" ); document.write( " 25000/15000 = (1 + r*8)
\n" ); document.write( " 25/15 - 1 = r*8
\n" ); document.write( " 10/15 = r*8
\n" ); document.write( " 10/(15 * 8) = r
\n" ); document.write( " r = 0.08333… ( 8.33333... % )
\n" ); document.write( " \n" ); document.write( "
\n" );