document.write( "Question 515279: a sum of rs 2000 is split between two investments, one paying 7% interest and the other paying 8%. if the return on 8% investment exceeds that on the 7% investment by rs 40, how much is invested at each rate? \n" ); document.write( "
Algebra.Com's Answer #343893 by mananth(16946)\"\" \"About 
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Part I 8.00% per annum ------------- x
\n" ); document.write( "Part II 7.00% per annum ------------ y
\n" ); document.write( " total investment 2000
\n" ); document.write( " Interest----- from I = 8.00% x
\n" ); document.write( " Interest from II= 7.00% y
\n" ); document.write( " greater by 40
\n" ); document.write( " 8.00% x = 7.00% y + 40
\n" ); document.write( " multiply by 100
\n" ); document.write( " 8 x - -7 y = 4000 --------1
\n" ); document.write( "x + y = 2000 -------- 2
\n" ); document.write( "eliminate y
\n" ); document.write( "Multiply 1 by 1
\n" ); document.write( "Multiply 2 by 7
\n" ); document.write( "we get
\n" ); document.write( "8 x - -7 y = 4000
\n" ); document.write( "7 x - 7 y = 14000
\n" ); document.write( "15 x = 18000
\n" ); document.write( "/ 15
\n" ); document.write( " x= 1200
\n" ); document.write( "Plug the value of x in in 1
\n" ); document.write( "9600 -7 y = 4000
\n" ); document.write( " -7 y = 4000 -9600
\n" ); document.write( " -7 y = -5600
\n" ); document.write( " / -7
\n" ); document.write( " y= 800
\n" ); document.write( "Rs 1200 at 8.00%
\n" ); document.write( "Rs 800 at 7.00%
\n" ); document.write( "
\n" ); document.write( "CHECK
\n" ); document.write( "96 = 56 + 40\r
\n" ); document.write( "\n" ); document.write( "m.ananth@hotmail.ca
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