Would assume Simple Interest.
I = PRT
R = I/PT Where R = Rate, I = Interest, P = Principal, T = Time
P = $100, T = 3 years, Interest, I = Amount - Principal = $125.97 - $100 = $25.97
R = I/PT
R = 25.97/(100*3)
R ≈ 0.0866
To percentage ≈ 0.0866 * 100% ≈ 8.66%
Rate ≈ 8.66%
Hope this helps.