Multiple choice

The difference between the C.I. and S.I. on an amount of Rs. 18,000 in 2 years was Rs. 405. What was the rate of interest % p.a. ?

  1. $10\%$
  2. $15\%$
  3. $20\%$
  4. $25\%$
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

For 2 years, the difference between compound interest and simple interest is given by the formula D = P * (r/100)^2. Plugging in the values: 405 = 18000 * (r/100)^2, so (r/100)^2 = 405/18000 = 0.0225. Thus, r/100 = 0.15, meaning r = 15%.

AI explanation

The difference between compound interest and simple interest for two years is given by the formula (Principal * Rate^2) / 10000. Substituting the given values, we get 405 = (18000 * Rate^2) / 10000. Simplifying this yields Rate^2 = 40500 / 18000 = 2.25, so the rate is 15%.

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