In a bank, principal increases continuously at the rate of r% per year. Find the value of r if Rs 100 double itself in 10 years (loge2 = 0.6931).
let t be time
p be principal
r be rate of interest
according the information principal increases at the rate of r% per year.
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Separating variables,
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Integrating both sides,
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Given that t = 0, p = 100.
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Now, if t = 10, then p = 2×100 = 200
So,
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So r is 6.93%.