Find the wrong term in the following number series- 1.25 6.25 17.5 57.5 247 1180

The series follows the pattern: multiply by n and add n²/25, where n increases by 1 each step (×5 + 0.2, ×6 + 1.44, ×7 + 3.92, ×8 + 6.4, ×9 + 9.76). Applying this pattern: 1.25 × 5 + 0.2 = 6.25, 6.25 × 6 + 1.44 = 38.94 (should be 17.5), 17.5 × 7 + 3.92 = 126.42 (should be 57.5), 57.5 × 8 + 6.4 = 466.4 (should be 243). The actual term 247 breaks the pattern - it should be 243. The correct wrong term is 247 (option C).