Question

The simple interest on a certain sum for 4 years at 9% per annum is R114 more than the simple interest Non the same sum for 3 years at 10% per annum. Find the sum.

Answer 1

Answer:

$Required \: sum = P = Rs \: 1900$

Step-by-step explanation:

i) Let the principal (P) = Rs x

Time (T) = 4 years

Rate of interest (R) = 9%

$Simple \: interest = I_{1}$

and

ii) The principal (P) = Rs x

Time (t) = 3 years

Rate of interest (r) = 10%

$Simple \: interest = I_{2}$

/* According to the problem given,

$I_{1} - I_{2} = Rs \:114$

$\implies \frac{PTR}{100} - \frac{Ptr}{100}=114$

$We \: know \: that ,\\\boxed { Simple \: interest (I) = \frac{ PTR }{100}}$

$\implies \frac{P}{100} ( TR- tr)= 114$

$\implies \frac{P}{100} ( 4\times 9- 3\times 10)= 114$

$\implies \frac{P}{100} ( 36- 30)= 114$

$\implies \frac{P}{100} \times 6= 114$

$\implies P =114 \times \frac{ 100}{6}\\= Rs\:1900$

Therefore,

$Required \: sum = P = Rs \: 1900$

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