If a certain sum of money becomes thrice of itself in 8 years 6 months at simple interest, then what will be the annual rate of interest?

Explanation

Let the principal be P. At simple interest, the amount becomes 3P in 8.5 years. Interest = 3P - P = 2P. Using the formula: SI = (P × R × T)/100, 2P = (P × R × 8.5)/100, R = (2 × 100) / 8.5 = 23.52%. Thus, the correct answer is 23.52 percent.