document.write( "Question 759213: At what rate of interest will a sum of money amount to Rs.5310 in 2 years and Rs.6120 in 4 years? Plz. give solution. \n" ); document.write( "
Algebra.Com's Answer #461941 by nerdybill(7384)\"\" \"About 
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At what rate of interest will a sum of money amount to Rs.5310 in 2 years and Rs.6120 in 4 years? Plz. give solution.
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\n" ); document.write( "Interest formula:
\n" ); document.write( "A = P(1+r)^t
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\n" ); document.write( "Let P = initial sum of money
\n" ); document.write( "and r = rate of interest
\n" ); document.write( "then from \"Rs.5310 in 2 years\" we get
\n" ); document.write( "5310 = P(1+r)^2 (equation 1)
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\n" ); document.write( "and from \"Rs.6120 in 4 years\" we get
\n" ); document.write( "6120 = P(1+r)^4 (equation 2)
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\n" ); document.write( "solve equation 1 for P:
\n" ); document.write( "5310 = P(1+r)^2
\n" ); document.write( "5310/(1+r)^2 = P
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\n" ); document.write( "substitute above into equation 2 and solve for r:
\n" ); document.write( "6120 = P(1+r)^4
\n" ); document.write( "6120 = 5310/(1+r)^2*(1+r)^4
\n" ); document.write( "6120/5310 = (1+r)^2
\n" ); document.write( "6120/5310 = (1+r)^2
\n" ); document.write( "1.1525423729 = (1+r)^2
\n" ); document.write( "1.0736 = 1+r
\n" ); document.write( ".0736 = r
\n" ); document.write( "or
\n" ); document.write( "7.4% = r
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