Determine the number of months required to get Rs. 25.5 as simple interest on Rs. 850 at 3.6% per annum.

Question

Determine the number of months required to get Rs. 25.5 as simple interest on Rs. 850 at 3.6% per annum.

1. A. 10 months (Correct answer)
2. B. 9 months
3. C. 8 months
4. D. 7 months

Correct Answer

Option A — 10 months

Detailed Solution & Explanation

The correct answer is 10 months.

Key Points

• Simple Interest formula: SI = (P x R x T) / 100.
• Substituting P = 850, R = 3.6 and SI = 25.5: 25.5 = (850 x 3.6 x T) / 100.
• 850 x 3.6 = 3,060, so 25.5 = 30.6T → T = 0.8333 years.
• Converting to months: 0.8333 x 12 = 10 months.

Additional Information

• Interest for one full year would be Rs. 30.60; since Rs. 25.50 is exactly 5/6 of that, the period is 5/6 of a year = 10 months — a faster route.
• Always convert the final answer into the unit the options use; leaving it in years is the usual slip here.