Question

c) What sum will amount to 27300 in 2 years, at compound interest, if the rates for the successive rates are 4 and 5 percent
per year?​

Answer 1

$Given , Amount (A) = Rs \:27300 , \\Rate \:of \: interest (R_{1}) = 4\% \: p.a , \:and \\rate \:of \: interest (R_{2}) = 5\% \:p.a$

$Let \: Sum ( Principal ) = Rs \: P$

$\boxed { \pink { P\Big( 1 + \frac{R_{1}}{100}\Big)\Big( 1 + \frac{R_{2}}{100}\Big) = A }}$

$\implies P\Big( 1 + \frac{4}{100}\Big)\Big( 1 + \frac{5}{100}\Big) = 27300$

$\implies P\Big( \frac{100+4}{100}\Big)\Big( \frac{100+5}{100}\Big) = 27300$

$\implies P\Big( \frac{104}{100}\Big)\Big( \frac{105}{100}\Big) = 27300$

$\implies P = \frac{27300 \times 100\times 100}{104 \times 105}$

$\implies P = Rs \: 25000$

Therefore.,

$\red{ Required \:sum } \green {= Rs \: 25000}$

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