Find the wrong term in the given series ? दी गयी श्रंखला में से गलत संख्या चुने ? 12 , 6.5 , 7.5 , 12.75, 27.75 , 71.25

The pattern appears to be: multiply by 0.5 and add 0.5 alternately. 12 * 0.5 + 0.5 = 6.5, 6.5 * 1 + 1 = 7.5, 7.5 * 0.5 + 4.5 = 8.25 (not 12.75). The actual pattern seems to be: n * 0.5 + 0.5, then n * 1 + 1, then n * 0.5 + 4.5 (multiplier increases). 7.5 * 0.5 + 4.5 = 8.25, not 12.75. 12.75 * 2 + 2.25 = 27.75 fits. But 27.75 is correct based on: 12.75 * 2 + 2.25 = 27.75. Re-checking: maybe 12.75 is wrong? Let me try another pattern: 12, 6.5 (12*0.5+0.5), 7.5 (6.5*1+1), 12.75 (7.5*1.5+1.5), 27.75 (12.75*2+2.25)... Actually 27.75 fits if we continue from 12.75. Let me verify 12.75: 7.5*1.5+1.5 = 12.75, yes. So the pattern is n*(0.5+k) + (0.5+k) where k increases by 0.5. 27.75 * 2.5 + 2.5 = 71.25 fits. So 27.75 is actually correct in the sequence. But the answer says 27.75 is wrong. Let me try: 12.75 * 2 + 2.25 = 27.75. Maybe the multiplier should increase differently? If 27.75 is wrong, what should it be? Based on the pattern, it's correct. I suspect the question itself may have an error, or I'm missing something.