If the simple interest on Rs 1000 for 2 years is Rs 100 what is the rate?

Explanation: SI = (P×R×T)/100 → 100 = (1000×R×2)/100 → 100 = 20R → R = 5%. Simple interest problems are standard in competitive exams. The ability to rearrange the SI formula to find principal rate or time is a key skill. Always identify which variable is unknown and rearrange accordingly before substituting values.