Question

a sum of money rs.12000 get doubled to rs.24000 in 8 years . what is the rate of interest

Answer 1

$Principal (P) = Rs \: 12000 ,\\Time (T) = 8 \:years \\Amount (A) = Rs \: 24000 \\Let \: Rate \: of \: interest = R$

$\boxed { \pink { Simple \: interest (I) = A - P }}$

$I = Rs \: 24000 - Rs \: 12000$

$\implies I = Rs \: 12000$

/* We know that,

$\boxed { \pink { R = \frac{100\times I }{PT } }}$

$R = \frac{ 100\times 12000 }{12000\times 8}\\= \frac{100}{8} \\= 12.5 \: \%$

Therefore.,

$\red { Rate \: of \: interest} \green { = 12.5 \% }$

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