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The compound interest on Rs. 30,000 at 7% per annum is Rs. 4,347. Find the period (in years).

Difficulty: Easy

Correct Answer: 2 years

Explanation:

Problem restatement
Given CI and rate, determine t such that P[(1 + r)t − 1] = CI.


Given data

  • P = 30,000; r = 7% = 0.07
  • CI = 4,347 ⇒ (1 + r)t − 1 = 4,347 ÷ 30,000 = 0.1449

Concept/Approach
Recognize the square of 1.07: (1.07)2 = 1.1449.


Step-by-step calculation
(1.07)t = 1 + 0.1449 = 1.1449Since (1.07)2 = 1.1449, we have t = 2 years


Verification/Alternative
Compute CI directly: 30,000[(1.07)2 − 1] = 30,000(0.1449) = 4,347.


Common pitfalls
Taking t = 1 (would give only 7%, not 14.49%).


Final Answer
2 years

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