Divide Rs 8000 into two parts so that simple interest on the 1st part for 2…

2025

Divide Rs 8000 into two parts so that simple interest on the 1st part for 2 years at 6.5% p.a. is equal to the compound interest on the 2nd part for 2 years at 5% p.a.?

  1. A.

    Rs. 2,000, Rs. 6,000

  2. B.

    Rs. 2,500, Rs. 5,500

  3. C.

    Rs. 3,000, Rs. 5,000

  4. D.

    None of these

Show answer & explanation

Correct answer: D

Concept: Simple Interest (SI) on a principal P for T years at rate R% p.a. is SI = (P × R × T) / 100. Compound Interest (CI) on a principal P for T years at rate R% p.a., compounded annually, is CI = P × [(1 + R/100)T − 1]. When a sum is split into two parts linked by an SI/CI condition, set up this equation and solve for the parts.

Applying to this question:

  1. Let the 1st part be Rs x, so the 2nd part is Rs (8000 − x).

  2. SI on the 1st part for 2 years at 6.5% p.a.: SI = (x × 6.5 × 2) / 100 = 0.13x.

  3. CI on the 2nd part for 2 years at 5% p.a.: CI = (8000 − x) × [(1.05)2 − 1] = (8000 − x) × 0.1025.

  4. Since SI = CI: 0.13x = 0.1025(8000 − x).

  5. Expand the right side: 0.13x = 820 − 0.1025x.

  6. Combine like terms: 0.13x + 0.1025x = 820, so 0.2325x = 820.

  7. Solve for x: x = 820 / 0.2325 ≈ 3526.88.

  8. So the 1st part ≈ Rs 3,526.88 and the 2nd part = 8000 − 3526.88 ≈ Rs 4,473.12.

Cross-check: This computed split (≈ Rs 3,526.88 and ≈ Rs 4,473.12) does not match any of the numeric splits offered — Rs. 2,000/Rs. 6,000; Rs. 2,500/Rs. 5,500; or Rs. 3,000/Rs. 5,000 — confirming that the correct choice is ‘None of these’.

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