Multiple choice

In each of the following questions, a question is followed by three statements numbered I, II and III. Read all the statements and find which information is/are necessary to answer. निम्नलिखित में से प्रत्येक प्रश्न में, तीन कथन I, II और III दिए गए हैं। सभी कथनों को पढ़ें और ज्ञात कीजिये कि उत्तर देने के लिए कौन सी जानकारी/जानकारियां आवश्यक है। The compound interest on a sum of Rs. 8000 is Rs. 2648. Find the rate of interest. 8000 रुपये की राशि पर चक्रवृद्धि ब्याज 2648 रुपये है। ब्याज दर ज्ञात कीजिये। Statement I: The simple interest on the same sum at the same rate is Rs. 2400. Statement II: Compound interest is compounded every four months. Statement II: The sum doubles itself in 25 years at the rate of 4% per annum. कथन I: समान राशि पर साधारण ब्याज 2400 रुपये है । कथन II: चक्रवृद्धि ब्याज की गणना प्रत्येक चार महीने में किया जाता है। कथन II: राशि 4% वार्षिक ब्याज की दर से 25 वर्षों में दोगुना हो जाती है।

  1. Only I and III केवल I तथा III

  2. All statements together are sufficient सभी कथन एक साथ पर्याप्त हैं

  3. Only I and II केवल I तथा II

  4. (I and II) or III (I तथा II) या III

  5. All statements together are not sufficient सभी कथन एक साथ पर्याप्त नहीं हैं
Reveal answer Fill a bubble to check yourself
E Correct answer
Explanation

We have Principal = Rs. 8000, Compound Interest = Rs. 2648, so Amount = Rs. 10648. The CI formula is A = P(1 + r/n)^(nt). Statement I gives Simple Interest = Rs. 2400, so 2400 = 8000 × r × t, meaning r × t = 0.3. Statement II says compounding is every 4 months (n = 3 times per year). Statement III discusses a different scenario (doubling at 4% in 25 years). The key issue: the question doesn't specify the time period t for which the CI was calculated. Without knowing t, we cannot determine r uniquely. None of the statements provide t. Even with all statements, we have insufficient information to find the rate.

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