A moneylender's income decreased by rs60 when the rate of interest dropped from 8% p.a. to 31/4% p.a..what was his principal?

Asked by abhishekgarg81187 | 12th Aug, 2018, 08:42: PM

Expert Answer:

begin mathsize 16px style let space principle space equals space rs. space straight P
Suppose space time comma space straight t space equals space 1 space year
Ler space straight r subscript 1 space equals space 8 percent sign space straight p. straight a. space and space straight r subscript 2 space equals space 31 over 4 percent sign straight p. straight a.
straight I space equals space fraction numerator straight P thin space cross times space straight r subscript 1 space cross times space straight t space over denominator 100 end fraction space and space space straight I space equals space fraction numerator straight P thin space cross times space straight r subscript 2 space cross times space straight t space over denominator 100 end fraction
rightwards double arrow straight I space equals space fraction numerator straight P thin space cross times 8 space over denominator 100 end fraction space and space space straight I space equals space fraction numerator straight P thin space cross times 31 space over denominator 400 end fraction
According space to space the space question comma
fraction numerator 8 straight P over denominator 100 end fraction minus fraction numerator 31 straight P over denominator 400 end fraction equals space 60
rightwards double arrow straight P over 100 open parentheses 8 space minus 31 over 4 close parentheses space equals space 60
rightwards double arrow straight P over 100 space cross times space 1 fourth space equals space 60
rightwards double arrow straight P space equals space 60 space cross times space 400 space equals space Rs. space 24000 end style

Answered by Yasmeen Khan | 13th Aug, 2018, 11:03: AM

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