A invests Rs.1100 at a rate of interest 20% on simple interest for a certain period of time while B invests Rs.1000 at a rate of interest of 10% on compound interest for the same period of time. The difference between the interests earned by A and B is Rs.224.5. Find the time duration for which both invested their money. (compounded half-yearly)
A invests Rs.1100 at a rate of interest 20% on simple interest for a certain period of time while B invests Rs.1000 at a rate of interest of 10% on compound interest for the same period of time. The difference between the interests earned by A and B is Rs.224.5. Find the time duration for which both invested their money. (compounded half-yearly) Correct Answer 2
Formula:
Let P = Principle, R = rate of interest and N = time period
Simple interest = PNR/100
Compound interest (half yearly) = P(1 + (R/2)/100)2n - P
Calculation:
Let time period of which both invested their money be n.
Simple interest = 1100 × 20 × n/100 = Rs.220n
Compound interest = 1000(1 + 5/100)2n - 1000
⇒ 220n - 1000(1 + 5/100)2n + 1000 = 224.5
By using trial - error method,
⇒ n = 2
∴ For two years, both invested their money.
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