Explanation
Principal amount (P) = Rs. 12,500
Amount after 4 years (A) = Rs. 15,500
Time (T) = 4 years
Interest (I) = A - P = Rs. 15,500 - Rs. 12,500 = Rs. 3,000
Rate of interest (R) = (I / P) × (1 / T) × 100%
= (3,000 / 12,500) × (1 / 4) × 100%
= 6%